Recording medium, recording apparatus, reproducing method, and reproducing device

ABSTRACT

A recording medium to which this invention is applied includes a first recording area 3 where a digital audio signal sampled at a predetermined sampling frequency and quantized by a predetermined number of bits is recorded, a first management area 2 where information for carrying out management of the digital audio signal recorded in the first recording area 3 is recorded, a second recording area 6 where a digital audio signal corresponding to the digital audio signal recorded in the first recording area 3 is recorded, and a second management area 5 where information for carrying out management of the digital audio signal recorded in the second recording area 6 is recorded, wherein discrimination data indicating that plural recording areas exist is recorded in the first management area 2. Thus, this recording medium has compatibility with the conventional CD player, and can be reproduced in the state of high sound quality by a higher rank reproducing equipment.

DESCRIPTION

1. Technical Field

This invention relates to a recording medium including plural recordingareas, a recording apparatus for recording information on such arecording medium, a reproducing method for reproducing informationrecorded on such a recording medium, and a reproducing apparatus towhich such a reproducing method is applied.

2. Background Art

Compact Discs (CDs) are delivered in the beginning as music CDs whichare a so called CD-DA (Compact Disc-Digital Audio), and the standardthereof has been extended to CDs for multimedia. As the representativestandard of CD, there are standardized

CD-DA format,

CD-ROM (Compact Disc-Read Only Memory) format,

CD-I (Compact Disc-Interactive) format, and

CD-ROM/XA (CD-ROM Extended Architecture) format.

The CD-DA format is the format for audio data. This CD-DA format is theformat which provides the basis of other CD formats, and prescribes(specifies) the physical structure and the signal processing system forthe disc.

The CD-ROM format is the format extended for computer data. In thisCD-ROM format, as the physical block structure, two modes of the mode 1where Error Detection Code (hereinafter abbreviated as EDC) and ErrorCorrection Code (hereinafter abbreviated as ECC) are added and the mode2 where EDC/ECC is omitted are standardized.

The CD-I format is the format extended so as to include picture data orcharacter data, etc. in addition to audio data. The block structure inthis CD-I format is the block structure of the mode 2 in the CD-ROMformat. In this CD-I format, as the physical block structure, two modesof the form 1 in which EDC/ECC is added and the form 2 in which EDC/ECCis omitted are standardized.

The CD-ROM/XA format prescribes that, for the purpose of allowingcomputer data and audio data to be synchronous with each other, thecomputer data and the audio data are caused to be interleaved. The blockstructure in this CD-ROM/XA format is the block structure of the mode 2in the CD-ROM format. In this CD-ROM/XA format, as the physical blockstructure, two modes of the form 1 in which EDC/ECC is added and theform 2 in which EDC/ECC is omitted are standardized.

Meanwhile, in recent years, there have been proposed CD-R (CompactDisc-Recordable) discs in which a recording surface on which organic(system) recording material is coated is provided on one surface of thedisc of which size is the same as that of the compact disc so thatarbitrary data can be written onto the recording surface by light beams.In the CD-R discs, the CD-MO (Compact Disc-Magneto Optical) format forrewritable CD and the CD-WO (Compact Disc-Write Once) format for writeonce type CD are standardized. In addition, CDs of various formats asdescribed above have been prepared by making use of the CD-R discs.

In the case of the format of CD, one track is of one collective filestructure in which data has been written only once, or segments of audiodata.

In the beginning, the CD-DA discs and/or the CD-ROM discs, etc. werereproduction (playback) only discs, and were single session (area) discsprovided with single session constituted with one track or moreconsisting of audio track where audio data is recorded and/or data trackwhere computer data is recorded. However, the (data) once writable CD-Rdiscs are adapted so that plural sessions can be provided on the disc.Thus, multi-session discs utilizing such CD-R disc have been provided.

Meanwhile, audio data which can be recorded on the CD-R disc by theCD-DA format is 16 bit data. Accordingly, it is impossible to recordaudio data of the master tape recorded by the number of bits more than16 bit, for example, as it is.

In view of the above, the so-called noise shaping or dither is utilizedby the super bit mapping in which auditory sense is taken intoconsideration, or the like to record audio data more than 16 bits ontothe CD-R disc by the CD-DA format, in the state where those audio dataare caused to be set of 16 bit data, without injuring the sound quality.

By these technologies, CD-R discs recorded by the CD-DA format have beenable to be reproduced by the ordinary CD player. However, since the dataquantity is essentially decreased, it was impossible to reproduce thesame sound as sound of the master tape.

Moreover, if the CD-ROM format is used, it becomes possible to recordaudio data of the number of bits more than 16 bits as described aboveonto the CD-R disc. However, since compatibility with CDs of the CD-DAformat is lost, such CD-R discs cannot be reproduced by the ordinary CDplayer.

Further, there is restriction in the conventional format of the CD-Rdisc. Namely, e.g., if CD-R disc prepared in such a manner that areasrespectively called audio session recorded by the CD-DA format and datasession recorded by the CD-ROM format are mixed on the same disc by theso-called multi-session format is reproduced by the ordinary CD player,since codes which might not be recognized are recorded, there is thepossibility that reproduction of audio data of the audio track recordedin the audio session may become impossible, and/or data of the datatrack recorded in the data session may be erroneously reproduced asaudio data.

This invention has been made in view of actual circumstances asdescribed above, and its object is to provide a recording medium whichcan maintain compatibility with the conventional CD player, and can bereproduced in the state of high sound quality at the reproducingapparatus of higher rank, a recording apparatus capable of recordingaudio data onto such a recording medium in the state where high soundquality is maintained, and a reproducing method and a reproducingapparatus for reproducing such recording medium in the state of highsound quality.

DISCLOSURE OF THE INVENTION

In order to solve the above-described problems, a recording medium ofthis invention includes a first recording area where a digital audiosignal sampled at a predetermined sampling frequency and quantized by apredetermined number of bits is recorded, a first management area whereinformation for carrying out management of the digital audio signalrecorded in the first recording area is recorded, a second recordingarea where a digital audio signal corresponding to the digital audiosignal recorded in the first recording area is recorded, and a secondmanagement area where information for carrying out management of thedigital audio signal recorded in the second recording area is recorded.

Moreover, the digital audio signal recorded in the first recording areais digital audio signals of 2 channels, and the digital audio signalrecorded in the second recording area is digital audio signals of 2channels corresponding to the digital audio signals of 2 channelsrecorded in the first recording area.

Further, the digital audio signal recorded in the first recording areais one of data portions of high order bits and low order bits obtainedby dividing the digital audio signal quantized by the predeterminednumber of bits, and the digital audio signal recorded in the secondrecording area is the other of the data portions of the digital audiosignal quantized by the predetermined number of bits.

Further, the digital audio signal recorded in the first recording areais a digital audio signal obtained by down-sampling one digital audiosignal obtained by band-dividing the digital audio signal sampled at thepredetermined sampling frequency, and the digital audio signal recordedin the second recording area is the other digital audio signal obtainedby band-dividing the digital audio signal sampled at the predeterminedsampling frequency.

Further, the digital audio signal recorded in the second recording areais a compressed signal.

Further, time code corresponding to the first recording area is recordedin the second recording area.

Further, in order to solve the above-described problems, a recordingapparatus of this invention is directed to a recording apparatus adaptedfor recording information onto a recording medium including pluralareas, the apparatus comprising: a speech processing section forsampling an audio signal from a sound source at a predetermined samplingfrequency, and for converting digital audio information thus obtainedinto information in a form adapted to be recorded onto the recordingmedium; and a recording section for recording the digital audioinformation converted at the speech processing section into a firstrecording area and a second recording area constituting the plural areasof the recording medium.

Further, the speech processing section includes: a first speechprocessing section for sampling an audio signal from a first soundsource at a predetermined sampling frequency, and for quantizing digitalaudio information thus obtained by a predetermined number of bits, and asecond speech processing section for sampling an audio signal from asecond sound source corresponding to the first sound source at asampling frequency which is the same as the predetermined samplingfrequency, and for compressing digital audio information thus obtained,and the recording section records the digital audio information from thefirst speech processing section into the first recording area of therecording medium, and for recording the digital audio information fromthe second speech processing section into the second recording area ofthe recording medium.

Further, the speech processing section includes: a quantizing sectionfor sampling an audio signal from a sound source at a predeterminedsampling frequency, and for quantizing digital audio information thusobtained by a predetermined number of bits; and a separating section forseparating the digital audio information thus obtained from thequantizing section into information of high order bits and low orderbits, and the recording section records the digital audio information ofthe high order bits from the separating section into the first recordingarea of the recording medium, and for recording the digital audioinformation of the low order bits from the separating section into thesecond recording area of the recording medium.

Further, the speech processing section includes: a quantizing sectionfor sampling an audio signal from a sound source at a predeterminedsampling frequency, and for quantizing digital audio information thusobtained by a predetermined number of bits; and a (frequency) banddividing section for band-dividing the digital audio information fromthe quantizing section at a frequency which is 1/n (n is integer) of thepredetermined sampling frequency so that dividing into two groups iscarried out, and the recording section records the digital audioinformation of one group of the two groups into the first recording areaof the recording medium, and for recording the digital audio informationof the other group into the second recording area of the recordingmedium.

Further, time code corresponding to the first recording area is recordedin the second recording area.

Further, the recording section includes a first recording head forrecording digital audio information into the first recording area, and asecond recording head for recording digital audio information into thesecond recording area.

Further, in order to solve the above-described problems, a reproducingmethod of this invention is directed to a reproducing method forreproducing digital audio information from a recording medium includinga first recording area where digital audio information is recorded, afirst management area where information for carrying out management ofthe digital audio information recorded in the first recording area isrecorded, a second recording area where digital audio informationcorresponding to the digital audio information recorded in the firstrecording area is recorded, and a second management area whereinformation for carrying out the digital audio information recorded inthe second recording area is recorded, the method including: a firststep of reading the information of the first management area by areproduction head to discriminate on the management information whichhas been read whether or not the second recording area exists; a secondstep of moving the reproduction head to the second management area inthe case where it has been discriminated at the first step that thesecond recording area exists; a third step of reading the information ofthe second management area by the reproduction head moved at the secondstep to read the digital audio information of the second recording areaon the basis of the information to store the digital audio informationwhich has been read into a first memory; a fourth step of moving thereproduction head to a data recording position within the firstrecording area where digital audio information corresponding to thedigital audio information from the second recording area stored in thefirst memory at the third step is recorded; and a fifth step of readingthe digital audio information of the first recording area by thereproduction head moved at the fourth step to store this digital audioinformation into a second memory, and to output the digital audioinformation stored in the first memory and the digital audio informationstored in the second m Further, a speed for writing digital audioinformation into the first memory is higher than a speed for reading outdigital audio information from the first memory, and a speed for writingdigital audio information into the second memory is higher than a speedfor reading out digital audio information from the second memory.

Further, the reproducing method includes: a sixth step of comparing astorage quantity of the second memory and a predetermined value; aseventh step such that when it is discriminated at the sixth step thatthe storage quantity of the second memory is above the predeterminedvalue, a procedure is taken to move the reproduction head to a datarecording position within the second recording area where digital audioinformation successive (continuous) to the digital audio informationstored in the first memory, and to read the digital audio information:and an eighth step of storing the digital audio information of thesecond recording area which has been read at the seventh step into thefirst memory, and outputting the digital audio information stored in thefirst memory and the digital audio information stored in the secondmemory while taking synchronization therebetween.

Further, the digital audio information recorded in the first recordingarea is digital audio information of 2 channels, and digital audioinformation recorded in the second recording area is digital audioinformation of 2 channels corresponding to the digital audio informationrecorded in the first recording area.

Further, the digital audio information recorded in the first recordingarea is digital audio information of high order bits of digital audioinformation quantized by a predetermined number of bits after undergonesampling at a predetermined sampling frequency, and the digital audioinformation recorded in the second recording area is digital audioinformation of low order bits of the quantized digital audioinformation.

Further, the digital audio information recorded in the first recordingarea is digital audio information obtained by band-dividing, at apredetermined frequency, digital audio information quantized by apredetermined number of bits after undergone sampling at a predeterminedsampling frequency so that grouping into digital audio information ofthe higher frequency band side and the lower frequency band side iscarried out to sample the digital audio information of one group at asampling frequency lower than the predetermined sampling frequency, andthe digital audio information recorded in the second recording area isdigital audio information obtained by compressing the digital audioinformation of the other group.

Further, the digital audio information recorded in the second recordingarea includes time code corresponding to the digital audio informationof the first recording area.

Further, a reproducing method of this invention is directed to areproducing method for reproducing digital audio information from arecording medium including a first recording area where digital audioinformation and address information are recorded in the state where theyare multiplexed, a first management area where information for carryingout management of the digital audio information recorded in the firstrecording area is recorded, a second recording area where digital audioinformation and address information corresponding to the first recordingarea are recorded in the state where they are multiplexed, and a secondmanagement area where information for carrying out management of thedigital audio information recorded in the second recording area isrecorded, the method including: a first reading step of reading thedigital audio information and the address information from the firstrecording area by a first reproduction section; a second reading step ofreading the digital audio information and the address information fromthe second recording area by a second reproduction section; an outputstep of outputting, on the basis of the digital audio information andthe address information obtained at the first reading step and thedigital audio information and the address information obtained at thesecond reading step, the digital audio information while takingsynchronization therebetween; a first discrimination step ofdiscriminating whether or not information storage quantity of a memorysection for temporarily storing the digital audio information from thesecond reproduction section is a predetermined value or more; areproduction section stand-by step such that in the case where it isdiscriminated at the first discrimination step that the storage quantityof the information stored in the memory section is the predeterminedvalue or more, a control is carried out such that the secondreproduction section is caused to be in stand-by state; a seconddiscrimination step of discriminaelow the predetermined value; and areproduction section re-start step such that it is discriminated at thesecond discrimination step that the storage quantity is below thepredetermined value, a control is carried out such that the secondreproduction section is restarted.

Further, the digital audio information recorded in the first recordingarea is digital audio information of 2 channels, and the digital audioinformation recorded in the second recording area is digital audioinformation of 2 channels corresponding to the digital audio informationrecorded in the first recording area.

Further, the digital audio information recorded in the first recordingarea is digital audio information of high order bits of digital audioinformation quantized by a predetermined number of bits after undergonesampling at a predetermined sampling frequency, and the digital audioinformation recorded in the second recording area is digital audioinformation of low order bits of the quantized digital audioinformation.

Further, the digital audio information recorded in the first recordingarea is digital audio information obtained by band-dividing, at apredetermined frequency, digital audio information quantized by apredetermined number of bits after undergoing sampling at apredetermined frequency so that grouping into digital audio informationof the higher frequency band side and the lower frequency band side iscarried out to sample the digital audio information of one group at asampling frequency lower than the predetermined sampling frequency, andthe digital audio information recorded in the second recording area isdigital audio information obtained by compressing the digital audioinformation of the other group.

Further, in order to solve the above-described problems, a reproducingapparatus of this invention is directed to a reproducing apparatus forreproducing digital audio information from a recording medium includinga first recording area where digital audio information is recorded, afirst management area where information for carrying out management ofthe digital audio information recorded in the first recording area isrecorded, a second recording area where digital audio informationcorresponding to the digital audio information recorded in the firstrecording area is recorded, and a second management area whereinformation for carrying out management of the digital audio informationrecorded in the second recording area is recorded, the apparatuscomprising: reproducing means for reproducing the digital audioinformation from the recording medium, first memory means for storingthe digital audio information which has been read from the firstrecording area by the reproducing means; second memory means for storingthe digital audio information which has been read from the secondrecording area by the reproducing means, first discrimination means fordiscriminating whether or not quantity of data stored in the firstmemory means is a predetermined quantity or more, second discriminationmeans for discriminating whether or not quantity of data stored in thesecond memory means is a predetermined quantity or more, moving meansfor moving the reproducing means, and control means for conducting acontrol to move the reproducing means to the second recording area onthe basis of the information of the first management area to store, intothe second memory means, the digital audio information which has beenread from the second recording area, whereby in the case where it isdiscriminated at the second discrimination means that quantity of datastored in the second memory means is the predetermined quantity or more,the control means is operative to move the reproducing means to thefirst recording area where digital audio information corresponding tothe digital audio information stored in the second memory means isrecorded to store, into the first memory means, the digital audioinformation which has been read from the first recording area to outputthe digital audio information from the first and second memory meanswhile taking synchronization therebetween.

Further, the digital audio information recorded in the first recordingarea is digital audio information of 2 channels, and the digital audioinformation recorded in the second recording area is digital audioinformation of 2 channels corresponding to the digital audio informationrecorded in the first recording area.

Further, the digital audio information of the second recording area iscompressed digital audio information.

Further, the digital audio information recorded in the first recordingarea is digital audio information of high order bits of digital audioinformation quantized by a predetermined number of bits after undergonesampling at a predetermined sampling frequency, and the digital audioinformation recorded in the second recording area is digital audioinformation of low order bits of the quantized digital audioinformation.

Further, the digital audio information recorded in the first recordingarea is digital audio information obtained by band-dividing, at apredetermined frequency, digital audio information quantized by apredetermined number of bits after undergone sampling at a predeterminedsampling frequency so that grouping into digital audio information ofthe higher frequency band side and the lower frequency band side iscarried out to sample the digital audio information of one group at asampling frequency lower than the predetermined sampling frequency; andthe digital audio information recorded in the second recording area isdigital audio information obtained by compressing the digital audioinformation of the other group.

Further, the digital audio information recorded in the second recordingarea includes time code corresponding to the digital audio informationrecorded in the first recording area.

Further, a reproducing apparatus of this invention is directed to areproducing apparatus adapted for reproducing digital audio informationfrom a recording medium including a first recording area where digitalaudio information and address information are recorded in the statewhere they are multiplexed, a first management area where informationfor carrying out management of the digital audio information recorded inthe first recording area is recorded, a second recording area wheredigital audio information and address information corresponding to thefirst recording area are recorded in the state where they aremultiplexed, and a second management area where information for carryingout management of the digital audio information recorded in the secondrecording area is recorded, the apparatus comprising: first reproducingmeans for reading the digital audio information and the addressinformation from the first recording area; second reproducing means forreading the digital audio information and the address information fromthe second recording area; memory means for storing the digital audioinformation from the second reproducing means; control means forcontrolling the memory means and the second reproducing means on thebasis of the address information from the first recording area and theaddress information from the second recording area; mixing means formixing the digital audio information reproduced by the first reproducingmeans and the digital audio information reproduced by the secondreproducing means; and output means for outputting digital audioinformation mixed at the mixing means.

Further, the digital audio information recorded in the first recordingarea is digital audio information of 2 channels, and the digital audioinformation recorded in the second recording area is digital audioinformation of 2 channels corresponding to the digital audio informationrecorded in the first recording area.

Further, the digital audio information of the second recording area iscompressed digital audio information.

Further, the digital audio information recorded in the first recordingarea is digital audio information of high order bits of digital audioinformation quantized by a predetermined number of bits after undergonesampling at a predetermined sampling frequency, and the digital audioinformation recorded in the second recording area is digital audioinformation of low order bits of the quantized digital audioinformation.

Further, the digital audio information recorded in the first recordingarea is digital audio information obtained by band-dividing, at apredetermined frequency, digital audio information quantized by apredetermined number of bits after undergone sampling at a predeterminedsampling frequency so that grouping into digital audio information ofthe higher frequency band side and the lower frequency band side iscarried out to sample the digital audio information of one group at asampling frequency lower than the predetermined sampling frequency; andthe digital audio information recorded in the second recording area isdigital audio information obtained by compressing the digital audioinformation of the other group.

In accordance with the recording medium of this invention, it ispossible to prepare a recording medium, e.g., a disc-shaped recordingmedium such that data are respectively collectively recorded in thefirst session consisting of the first management area and the firstrecording area and the second session consisting of the secondmanagement area and the second recording area. Further, data can berespectively recorded by different formats with respect to the firstsession and the second session. In addition, digital audio informationto be recorded by the CD-DA format is recorded into the first session,and digital audio information attached to the digital audio informationrecorded in the first session is recorded into the second session,thereby making it possible to prepare a recording medium adapted so thataudio data can be recorded in the state of high sound quality andcompatibility with the conventional CD player is maintained.

Moreover, the recording medium is caused of a structure such thatdigital audio information of 4 channels are recorded into respectivesessions by 2 channels so that the digital audio information is recordedat least into the first session by the CD-DA format, thereby making itpossible to prepare a recording medium adapted so that audio data can berecorded in the state of high sound quality and compatibility with theconventional CD player is maintained.

Further, e.g., the recording medium is caused to be of a structure suchthat the portion (digital audio information of bits) up to 16 bits ofdigital audio information more than 16 bits is recorded into the firstsession by the CD-DA format, and digital audio information of theremaining bits is recorded into the second session, e.g., by the CD-ROMformat, thereby making it possible to prepare a recording medium adaptedso that audio data can be recorded in the state of high sound qualityand compatibility with the conventional CD player is maintained.

In addition, e.g., the recording medium is caused to be of a structuresuch that digital audio information sampled at a sampling frequencyprescribed (specified) by the ordinary CD-DA format is band-divided at apredetermined frequency, e.g., a frequency which is one half (1/2) ofthe sampling frequency so that grouping into digital audio informationof the higher frequency band side and the lower frequency band side ofthe frequency to down-sample the digital audio information of the lowerfrequency band side to record it into the first session by the CD-DAformat, and to record the digital audio information of the higherfrequency band side into the second session, e.g., by the CD-ROM format,thereby making it possible to prepare a recording medium adapted so thataudio data can be recorded in the state of high sound quality andmaintain compatibility with the conventional CD player is maintained.

Moreover, in accordance with the recording apparatus of this invention,the speech processing section samples an audio signal from the soundsource at a predetermined sampling frequency to allow it to be digitaldata, and to convert the digital data into data in a form adapted to berecorded onto a recording medium including plural recording areas. Inthis case, the recording medium is assumed to be constituted by thefirst session of the structure including the first management area andthe first recording area, and the second session of the structureincluding the second management area and the second recording area, andthe speech converting section converts digital data to be recorded intothe first session into CD-DA format data, and converts digital data tobe recorded into the second session into CD-ROM format data. Asdescribed above, the recording section records the CD-DA format datainto the first recording area, and records the CD-ROM format data intothe second recording area.

Further, in the case where the speech processing section is composed ofthe first speech processing section and the second speech processingsection, the first speech processing section changes audio signals of 2channels from the first sound source into digital data thereafter toquantize the digital data to thereby convert it into CD-DA format data,and the second speech processing section changes, e.g., audio signals of2 channels from the second sound source corresponding to the first soundsource into digital data thereafter to compress the digital data tothereby convert it into CD-ROM format data. In addition, the recordingsection records digital data from the first speech processing sectioninto the first recording area, and records digital data from the secondspeech processing section into the second recording area.

Further, in the case where the speech processing section is composed ofthe quantizing section and the separating section, the quantizingsection samples an audio signal from the sound source at a predeterminedsampling frequency to convert it into sampled data (digital data), andto quantize this sampled data (digital data) to convert it into digitaldata more than 16 bits, and the separating section allows the digitaldata more than 16 bits obtained at the quantizing section to undergoseparating conversion such that, e.g., digital data of high order 16bits is changed into CD-DA format data and digital data of other loworder bits is changed into CD-ROM format data. The recording sectionrecords, e.g., CD-DA format data into the first recording area, andrecords the CD-ROM format data into the second recording area.

Further, in the case where the speech processing section is composed ofthe quantizing section and the band-dividing section, the quantizingsection samples an audio signal from the sound source at a predeterminedsampling frequency to convert it into sampled data (digital data), andquantizes this sampled data (digital data) to thereby convert it intodigital data more than 16 bits, and the band-dividing sectionband-divides the digital data at a frequency which is 1/n (n is integer)of the predetermined sampling frequency. Namely, an audio signal isquantized after undergone sampling at a sampling frequency twice greaterthan 44.1 kHz which is the sampling frequency prescribed (specified) by,e.g., the CD-DA format to divide the quantized digital data into twogroups of digital data of the higher frequency band side and the lowerfrequency band side of the frequency of 44.1 kHz to convert the digitaldata of the lower frequency side into the CD-DA format data, and toconvert the digital data of the higher frequency side into CD-ROM formatdata. The recording section records the CD-DA format data into the firstrecording area, and records the CD-ROM format data into the secondrecording area.

Further, in the case where the recording section is composed of thefirst recording head and the second recording head, the first recordinghead carries-out recording by the CD-DA format with respect to the firstrecording area, and the second recording head carries out recording bythe CD-ROM format with respect to the second recording area.

Further, in accordance with the reproducing method of this invention, atthe first step, information of the first management area of therecording medium is read, whereby whether or not the second recordingarea exists is discriminated on the basis of the management information.When it is discriminated at the first step that the second recordingarea exists, access to the second management area where information forcarrying out digital audio information of the second recording area isrecorded is provided at the second step. At the third step, the digitalaudio information of the second recording area is read on the basis ofthe management information of the second management area to which accesshas been provided at the second step, and the digital audio informationthus read is stored into the first memory. At the fourth step, access todata recording position within the first recording area where digitalaudio information corresponding to the digital audio information storedin the first memory is recorded is provided. At the fifth step, thedigital audio information recorded at the data recording positionaccessed at the fourth step is read out from the first recording area,and the digital audio information thus read out is stored into thesecond memory. Thus, the digital audio information stored in the firstmemory at the third step and the digital audio information stored in thesecond memory is outputted in a manner synchronous with each other.

Further, at the sixth step, the storage quantity of data of the secondmemory in which digital audio information is stored at the fifth stepand a predetermined value, e.g., the allowed storage quantity of thefirst memory are compared with each other. When the storage quantity ofdata of the second memory is above the predetermined value, theprocessing operation proceeds to the seventh step. At the seventh step,access to data recording position within the second recording area wheredigital audio information successive (subsequent) to the digital audioinformation stored in the first memory is recorded is provided. Thus,this digital audio information is read out. At the eighth step, digitalaudio information from the second recording area which has been read outat the seventh step is temporarily stored into the first memory, and thedigital audio information stored in this first memory and the digitalaudio information stored in the second memory at the fifth step areoutputted in a manner synchronous with each other.

Further, in the case where there is used a recording medium such thatdigital audio information of 2 channels are recorded in the firstrecording area and digital audio information of 2 channels correspondingto the digital audio information recorded in the first recording areaare recorded in the second recording area, at the fifth step, thedigital audio information recorded in the first recording area and thedigital audio information recorded in the second recording area aresynchronously reproduced. Thus, high sound quality digital audioinformation of multi-channel is outputted.

Further, e.g., in the case where there is used a recording medium suchthat the portion (digital audio information of bits) up to 16 bits ofdigital audio information more than 16 bits is recorded in the firstrecording area, and digital audio information of the remaining bits isrecorded in the second area, at the fifth step, the digital audioinformation recorded in the first recording area and the digital audioinformation recorded in the second recording are synchronouslyreproduced. Thus, high sound quality digital audio information of whichnumber of bits has been increased is outputted.

Further, in the case where there is used a recording medium such that,e.g., digital audio information obtained by band-dividing digital audioinformation sampled at a sampling frequency prescribed (specified) bythe ordinary CD-DA format at a predetermined frequency, e.g., afrequency which is one half of the sampling frequency to down-sample thedigital audio information of the lower frequency band side with respectto the frequency which is one half of the sampling frequency is recordedin the first recording area, and digital audio information obtained bycompressing the digital audio information of the higher frequency bandside is recorded in the second recording area, at the fifth step, thecompressed digital audio information is restored (reconstructed), andthe digital audio information thus restored and the digital audioinformation recorded in the first recording area are synchronouslyreproduced. Thus, high sound quality digital audio information of theso-called high-sampling system (i.e., sampling frequency has beenincreased) is outputted.

Further, in accordance with the reproducing method of this invention, atthe first reading step, the first reproduction section reads digitalaudio information and address information from the first recording areaof the recording medium. At the second reading step, the secondreproduction section reads digital audio information and addressinformation from the second recording area of the recording medium. Atthe output step, digital audio information based on both digital audioinformation recorded in the respective recording area is outputted onthe basis of both address information recorded in the respectiverecording area. At the first discrimination step, whether or not storagequantity of the digital audio information from the second reproductionsection temporarily stored in the memory section reaches a predeterminedquantity, e.g., allowed storage quantity of the memory section isdiscriminated. The reproduction section standby step is the stepexecuted when it is discriminated at the first discrimination step thatquantity of information stored in the memory section reaches the allowedstorage quantity. At this step, the second reproduction section iscontrolled so that it is in stand-by state. At the second discriminationstep, whether or not the information storage quantity of the memorysection is below the predetermined quantity, i.e., whether or notsufficient room (memory capacity) is provided (ensured) isdiscriminated. The reproduction section re-start step is the stepexecuted when it is discriminated at the second discrimination step thatsufficient room (memory capacity) is provided (ensured) in the memorysection. At this step, the second reproduction section is controlled sothat it is restarted.

Further, in the case where there is used a recording medium such thatdigital audio information of 2 channels are recorded in the firstrecording area, and digital audio information of 2 channelscorresponding to the digital audio information recorded in the firstrecording area are recorded in the second recording area, at the firstreading step, the digital audio information and the address informationrecorded in the first recording area are read. At the second readingstep, the digital audio information and the address information recordedin the second recording area are read. At the output step, there aresynchronously reproduced both digital audio information recorded in therespective recording areas on the basis of address information recordedin the respective recording areas which have been read at the first andsecond reading steps. Thus, high sound quality digital audio informationof the multi-channel is outputted.

Further, e.g., in the case where there is used a recording medium suchthat the portion (digital audio information of bits) up to 16 bits ofdigital audio information more than 16 bits is recorded in the firstrecording area, and digital audio information of the remaining bits isrecorded in the second recording area, at the first reading step, thedigital audio information and the address information recorded in thefirst recording area are read. At the second reading step, the digitalaudio information and the address information recorded in the secondrecording area are read. At the output step, there are synchronouslyoutputted both digital audio information recorded in the respectiverecording areas on the basis of address information recorded in therespective recording areas which have been read at the first and secondreading steps. Thus, high sound quality digital audio information ofwhich number of bits has been increased is outputted.

Further, e.g., in the case where there is used a recording medium suchthat digital audio information obtained by band-dividing digital audioinformation sampled at a sampling frequency prescribed (specified) bythe ordinary CD-DA format at a predetermined frequency, e.g., afrequency which is one half of the sampling frequency to down-sample thedigital audio information of the lower frequency band side with respectto the frequency which is one half of the sampling frequency is recordedin the first recording area, and information obtained by compressing thedigital audio information of the higher frequency band side is recordedin the second recording area, at the first reading step, the digitalaudio information and the address information recorded in the firstrecording area are read. At the second reading step, compressed digitalaudio information and address information recorded in the secondrecording area are read, and the compressed information is furtherrestored (reconstructed). At the output step, there are synchronouslyoutputted both digital audio information recorded in the respectiverecording areas on the basis of address information recorded in therespective recording areas. Thus, high sound quality digital audioinformation of the so-called high-sampling system (i.e., samplingfrequency has been increased) is outputted.

Further, in accordance with the reproducing apparatus of this invention,the reproducing means reproduces digital audio information from therecording medium, the first memory means stores digital audioinformation from the first recording area of the recording medium, andthe second memory means stores digital audio information from the secondrecording area of the recording medium. The first discrimination meansdiscriminates whether or not quantity of data stored in the first memorymeans reaches a predetermined quantity, e.g., allowed storage quantity,and the second discrimination means discriminates whether or notquantity of data stored in the second memory means reaches apredetermined quantity, e.g., allowed storage quantity. The moving meansmoves the reproduction means. The control means conducts a control toallow the moving means to undergo movement operation on the basis ofinformation of the first management area where information for carryingout management of the first recording area is recorded to allow it toprovide access to the second recording area to allow the second memorymeans to store digital audio information read out from the datarecording position to which access has been provided, whereby when it isdiscriminated on the basis of a result from the second discriminationmeans that quantity of data stored in the second memory means is thepredetermined quantity or more, the control means conducts a control toallow the moving means to undergo movement operation to allow it toprovide access to the first recording area to allow the first memorymeans to store digital audio information read out from the datarecording position to which access has been provided, and to conduct acontrol to output digital audio information from the first and secondmemory means in a manner synchronous with each other.

Further, in the case where there is used a recording medium such thatdigital audio information of 2 channels are recorded in the firstrecording area, and digital audio information of 2 channelscorresponding to the digital audio information recorded in the firstrecording area are recorded in the second recording area, the firstmemory means stores digital audio information recorded in the firstrecording area, and the second memory means stores digital audioinformation recorded in the second recording area. The control meanscarries out control of the first and second memory means to allow therespective memory means to synchronously output the digital audioinformation stored therein. Thus, high sound quality digital audioinformation of multi-channel is outputted.

Further, e.g., in the case where there is used a recording medium suchthat the portion (bits of digital audio information of bits) up to 16bits of digital audio information more than 16 bits is recorded in thefirst recording area, and digital audio information of the remainingbits is recorded in the second recording area, the first memory meansstores digital audio information recorded in the first recording area,and the second memory means stores digital audio information recorded inthe second recording area. The control means controls the first andsecond memory means to allow the respective memory means tosynchronously output digital audio information stored therein. Thus,high sound quality digital audio information of which number of bits hasbeen increased is outputted.

Further, e.g., in the case where there is used a recording medium suchthat digital audio information obtained by band-dividing digital audioinformation sampled at a sampling frequency prescribed (specified) bythe ordinary CD-DA format at a predetermined frequency, e.g., afrequency which is one half of the sampling frequency to down-sample thedigital audio information of the lower frequency band side with respectto the frequency (band) which is one half of the sampling frequency isrecorded in the first area, and information obtained by compressing thedigital audio information of the higher frequency band side is recordedin the second recording area, the first memory means stores the digitalaudio information recorded in the first recording area, and the secondmemory means stores compressed digital audio information recorded in thesecond recording area. The control means conducts a control to restore(reconstruct) the compressed digital audio information, and conducts acontrol to allow the first memory means to output digital audioinformation stored therein and the restored digital audio information ina manner synchronous with each other. Thus, high sound quality digitalaudio information of the so-called high-sampling system (i.e., samplingfrequency has been increased) is outputted.

Further, in accordance with the reproducing apparatus of this invention,the first reproducing means reads digital audio information and addressinformation from the first recording area of the recording medium, andthe second reproduction means reads digital audio information andaddress information from the second recording area of the recordingmedium. The memory means stores digital audio information from thesecond reproduction means. The control means carries out, on the basisof both address information stored in the respective memory means, sucha control to allow the second reproduction means to be in stand-by statewhen information storage quantity of the memory means reaches theallowed quantity. The mixing means mixes the digital audio informationwhich has been read by the first reproducing means and the digital audioinformation from the memory means, and the output means outputs digitalaudio information mixed at the mixing means.

Further, in the case where there is used a recording medium such thatdigital audio information of 2 channels are recorded in the firstrecording area and digital audio information of 2 channels correspondingto the digital audio information recorded in the first recording areaare recorded in the second recording area, the first reproducing meansreads digital audio information and address information recorded in thefirst recording area, and the second reproducing means reads digitalaudio information and address information recorded in the secondrecording area. The mixing means mixes, on the basis of the addressinformation recorded in the respective recording areas which have beenread by the first and second reproducing means, both digital audioinformation recorded in the respective recording areas while takingsynchronization therebetween. The output means outputs high soundquality digital audio information of multi-channel.

Further, e.g., in the case where there is used a recording medium suchthat the portion (bit of digital audio information) up to 16 bits ofdigital audio information more than 16 bits is recorded in the firstrecording area, and digital audio information of the remaining bits isrecorded in the second recording area, the first reproducing means readsdigital audio information and address information recorded in the firstrecording area, and the second reproducing means reads digital audioinformation and address information recorded in the second recordingarea. The mixing means mixes, on the basis of address informationrecorded in the respective recording areas which have been read by thefirst and second reproducing means, both digital audio informationrecorded in the respective recording areas while taking synchronizationtherebetween. The output means outputs high sound quality digital audioinformation of which number of bits has been increased.

In addition, e.g., in the case where there is used a recording mediumsuch that digital audio information obtained by band-dividing digitalaudio information sampled at a sampling frequency prescribed (specified)by the ordinary CD-DA format at a predetermined frequency, e.g., afrequency which is one half (1/2) of the sampling frequency todown-sample the digital audio information of the lower frequency bandside with respect to the band of the frequency which is one half (1/2)of the sampling frequency is recorded in the first recording area, andinformation obtained by compressing the digital audio information of thehigher frequency band side is recorded in the second recording area, thefirst reproducing means reads digital audio information and addressinformation recorded in the first recording area, and the secondreproducing means reads compressed digital audio information and addressinformation recorded in the second recording area. The mixing meansmixes, on the basis of the address information which has been read bythe first reproducing means and address information obtained, e.g., byallowing compressed information to undergo decoding processing at adecoding section, both digital audio information recorded in therespective recording areas while taking synchronization therebetween.The output means outputs high sound quality digital audio information ofthe so-called high-sampling system (i.e., sampling frequency has beenincreased).

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are views showing the configuration of a recordingmedium to which this invention is applied.

FIG. 2 is a view for explaining CIRC frame which is data format of therecording medium.

FIG. 3 is a view for explaining sub coding based on the CIRC frame.

FIG. 4 is a view showing data format of Q channel of the sub coding.

FIG. 5 is a view showing data format of Q channel recorded in managementarea of the recording medium.

FIG. 6 is a block diagram showing the configuration of a firstembodiment of a recording apparatus to which this invention is applied.

FIG. 7 is a block diagram showing the configuration of speech processingsection of the recording apparatus.

FIG. 8 is a block diagram showing the configuration of a secondembodiment of the recording apparatus to which this invention isapplied.

FIG. 9 is a block diagram showing the configuration of a first modifiedexample of the recording apparatus.

FIG. 10 is a block diagram showing the configuration of a secondmodified example of the recording apparatus.

FIGS. 11A-11C are a block diagram and views showing the configuration ofa third modified example of the recording apparatus.

FIG. 12 is a block diagram showing the configuration of a thirdembodiment of the recording apparatus to which this invention isapplied.

FIG. 13 is a block diagram showing the configuration of a firstembodiment of a reproducing apparatus to which this invention isapplied.

FIG. 14 is a flowchart for explaining a reproducing method to which thisinvention is applied, i.e., based on the reproducing apparatus of thefirst embodiment.

FIGS. 15A and 15B are views for explaining the operation of memory ofthe reproducing apparatus.

FIG. 16 is a time chart showing data write/data read timings withrespect to two memories.

FIG. 17 is a block diagram showing the configuration of a first modifiedexample of the reproducing apparatus to which this invention is applied.

FIG. 18 is a block diagram showing the configuration of a secondmodified example of the reproducing apparatus.

FIG. 19 is a block diagram showing the configuration of a third modifiedexample of the reproducing apparatus.

FIGS. 20A-20C are a block diagram and views showing the configuration ofa second embodiment of the reproducing apparatus to which this inventionis applied.

FIG. 21 is a flowchart for explaining a reproducing method to which thisinvention is applied, i.e., based on the reproducing apparatus of thesecond embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of a recording medium, a recording apparatus, areproducing method, and a reproducing apparatus will now be describedwith reference to the attached drawings. In the following description,explanation will be given by taking the example where CD-R disc which isthe disc-shaped recording medium is used as the recording medium, theexample where a recording apparatus for disc-shaped recording mediumwhich is adapted for recording digital audio information onto such aCD-R disc is used as the recording apparatus, and the example where areproducing method and a reproducing apparatus for disc-shaped recordingmedium which are adapted for reproducing digital audio informationrecorded on such a CD-R disc are used as the reproducing method and thereproducing apparatus.

For example, as shown in FIGS. 1A and 1B, CD-R disc 1 includes a firstrecording area 3 where a digital audio signal (information) sampled at apredetermined sampling frequency and quantized by a predetermined numberof bits is recorded, a first management area 2 where information forcarrying out management of the digital audio signal recorded in thefirst recording area is recorded, a second recording area 6 where adigital audio signal corresponding to the digital audio signal recordedin the first recording area 3 is recorded, and a second management area5 where information for carrying out management of the digital audiosignal recorded in the second recording area 6 is recorded.

Moreover, at the CD-R disc 1, a center hole 8 is provided at the centralportion thereof. This CD-R disc is the so-called multisession disc wherea first session 9 is formed by the first management area 2, the firstrecording area 3 and a first lead-out area 4 corresponding to theseareas, and a second session 10 is formed by the second management area5, the second recording area 6 and a second lead-out area 7corresponding to these areas. In this case, data of the CD-DA format maybe written (recorded) into the first session 9, and data of the CD-ROMformat may be written into the second session 10.

Prior to explanation management of address information on the recordingmedium of this invention, a sub coding frame will now be described.

As the error correction code of the CD system such as CD-DA or CD-ROM,etc., CIRC (Cross Interleaved Reed Solomon Code) is employed. In this CDsystem, signals recorded on the disc-shaped recording medium are signalssampled at a sampling frequency of 44.1 kHz. In addition, these sampleddata are collected into respective one CIRC frames every data of 6sampling areas.

The format of signals collected into respective one CIRC frames is suchthat, as shown in FIG. 2, for example, there are provided, within eachCIRC frame 85, a synchronization (sync.) pattern data area 81 of 24bits, a sub coding area 82 of 14 bits, a program data area 83 consistingof 16 program data D0˜D15 respectively having 14 bits, a parity dataarea 84 consisting of 4 parity data P0˜P3 respectively having 14 bits, adifferent program data area 83, and a different parity data area 84.Moreover, in order to couple data of respective areas, blank areas of 3bits are provided with respect to respective portions. Accordingly, eachCIRC frame 85 includes of data 724 bits in total.

Further, the state where 98 CIRC frames 85 are collected (gathered) tocouple data of respective areas of the respective CIRC frames 85 afterundergoing sequencing is shown in FIG. 3.

As shown in the FIG. 3 mentioned above, each block 89 formed bycollecting 98 CIRC frames 85 consists of frame synchronization (sync.)pattern portion 86, sub coding portion 87 and data & parity portion 88.

In addition, the sub coding portion 87 includes synchronization (sync.)pattern of 98 CIRC frames, and data portions defined by eight symbols ofP, Q, R, S, T, U, V, W. Particularly, the data portions defined bysymbols of P, Q are used for control of access operation of thereproducing apparatus.

In this case, in respective areas shown in FIG. 1, addresses forindicating absolute positions on the CD-R disc 1 are given (allocated).These addresses are caused to undergo management by the data portiondefined by the symbol of Q.

FIG. 4 shows the format of the first session 9, i.e., the data portiondefined by the symbol of Q in the CD-DA format.

The data structure prescribed (provided) by this format is of the dataconfiguration in which information frames 120 each consisting of trackNo. portion 101, index portion 102, elapsed time portion 110, 0 (zero)portion 106 and absolute time portion 111 are repeated. Moreparticularly, the elapsed time portion 110 consists of min. (minutes)component portion 103, sec. (second) component portion 104 and frame No.component portion 105, and the absolute time portion 111 similarlyconsists of min. component portion 107, sec. component portion 108 andframe No. component portion 109. The frame No. component portions 105,109 are both numerals for further minutely dividing 1 second.

Moreover, data of respective portions consist of data of 8 bits, and arerepresented by two digits (figures) represented by BCD (Binary CodedDecimal), for example.

In FIG. 4, in the case where data TNO of the track No. portion 101 is"01"˜"99", this data TNO represents movement No. so called track No.indicating order of data recorded into the first recording area 3. Atthe elapsed time portion 110 and the absolute time portion 111, positionwhere data corresponding to track No. in the first recording area 3 isrecorded in the data & parity portion 88 is indicated. Namely, this dataserves as address of the data & parity portion 88.

Further, the index portion 102 is the portion provided by furtherminutely dividing the movement In this example, in the case where dataIX of the index portion 102 is "00", this data IX indicates that theinformation frame 120 is the information frame in which data indicatingpause area between movements is recorded. Particularly, start positionof pause preceding (earlier) by one movement is caused (assumed) to be 0min. 0 sec. 0 frame, and the above-mentioned data IX is used as theposition of reference of data indicated at the elapsed time portion 110and the absolute time portion 111. In addition, 0 (zero) is insertedinto the 0 portion 106.

In this example, times from the starts of respective movements arerecorded in the elapsed time section 110. These times are continued tobe added until the pause area appears, and start for a second time from0 (zero) when the track No. is updated. On the contrary, times addedfrom position of reference or absolute times are recorded in theabsolute time portion 111.

Moreover, in the case where data TNO of the track No. portion 101 is"AA", this data TNO indicates that the information frame 120 isinformation frame of the first lead-out area 4.

Particularly, in the case where data TNO is "00", this data TNOindicates that the information frame 120 is data within the firstmanagement area 2. The format in this case is repetition of the datastructure shown in FIG. 5.

In FIG. 5, in the case where data PO of point portion 112 is, e.g.,"00"˜"99", this data PO indicates that the information frame 120 is theinformation frame indicating absolute times at which respectivemovements indicated by the data PO start, and respective data recordedin the absolute time portion 111 indicate absolute times at whichrespective movements start. In this example, the start position of thefirst pause is caused (assumed) to the 0 hour 0 min. 0 frame.

Moreover, in the case where data PO is "AO", this data PO indicates thatthe information frame 120 is the information frame in which the firstmovement No. is indicated, and data PMIN recorded in the min. componentportion 107 of the absolute time portion 111 indicates the firstmovement No., and "00" is recorded as data PSEC, PFR in the min.component portion 107 and the sec. component portion 108.

Further, in the case where data PO is "A1", this data PO indicates thatthe information frame 120 is information frame in which the lastmovement No. is indicated. Last movement No. is recorded as data PMIN inthe min. component portion 107, and "00" is recorded as data PSEC, PFRin the sec. component portion 108 and the frame No. component portion109.

In addition, in the case where data PO is "A2", this data PO indicatesthat the information frame 120 is the information frame in whichabsolute time at which the first lead-out area 4 starts is indicated.Absolute time at which the first lead-out area 4 starts is recorded asdata PMIN, PSEC, PFR in the absolute time portion 111.

In this example, in any case described above, "00" is recorded inrespective data portions of the elapsed time portion 110.

Further, presence or absence of the second session 10 is also indicatedat the point portion 112. For example, when "BO" is assumed to bewritten as data PO in the point portion 112, this data PO indicates thatthe second management area 5 is provided at the outer circumferentialportion of the pause portion after the first lead-out area 4, andabsolute time indicating this position is indicated, e.g., at the min.component portion 103, the sec. component portion 104 and the frame No.portion 105 of the elapsed time portion 110. It is to be noted thatabsolute time indicating start position of the second management area 5may be recorded not only in the elapsed time portion 110, but also inthe absolute time portion 111.

Further, in the case where data corresponding to data recorded in thefirst recording area 3 is recorded in the second recording area 6,information frame in which the point portion 112 is "E0" is provided. Inthe case where such information frame is absent, it is indicated thatcorresponding disc is a disc such that only character data is recordedin the second management area 5 of the second session 10, and no data isrecorded in the second recording area 6, which is so-called disc withcharacter.

It is to be noted that while the example where information frame inwhich "B0" is recorded in the point portion 112 is provided asdiscrimination data indicating presence or absence of the second session10 has been taken, this invention is not limited to such implementation,but information frame in which "C0" is recorded may be employed as thediscrimination data. While information frame in which "E0" is recordedis provided as discrimination data for discriminating between the CD-Rdisc 1 and the disc with character, this invention is not limited tosuch implementation also in this case, but any other kind of informationframes may be used.

In addition, similarly, digital audio information of the secondrecording area 6 is caused to undergo management as described above asthe ordinary CD-ROM format by the information frame of the secondmanagement area 5.

A more practical example of the CD-R disc will now be described inconjunction with a first embodiment of a recording apparatus forrecording data onto CD-R disc as described above.

As shown in FIG. 6, for example, the recording apparatus of this firstembodiment is the recording apparatus adapted for recording informationonto CD-R disc 1 including plural recording areas, and includes a speechprocessing section 23 for sampling an audio signal from the sound sourceat a predetermined sampling frequency, and for converting digital audioinformation (signal) thus obtained into digital audio information in aform adapted to be recorded onto the CD-R disc 1, and a recordingsection 18 for recording the digital audio information processed at thespeech processing section 23 into the first session 9 and the secondsession 10 of the CD-R disc 1.

Moreover, as shown in FIG. 7, for example, the speech processing section23 includes a first speech processing section 16 for sampling an audiosignal from a first sound source at a predetermined sampling frequency,and for quantizing digital audio information thus obtained by apredetermined number of bits, and a second speech processing section 17for sampling an audio signal from a second sound source corresponding tothe first sound source at the same sampling frequency as thepredetermined sampling frequency, and for compressing digital audioinformation thus obtained. In addition, the recording section 18 recordsthe digital audio information from the first speech processing section16 into the first recording area 3 of the first session 9, and recordsthe digital audio information from the second speech processing section17 into the second recording area 6 of the second session 10.

In more practical sense, a first forward microphone 12 and a secondforward microphone 13 are microphones for forward channels, and a firstbackward microphone 14 and a second backward microphone 15 aremicrophones for backward channels. In this case, the so-calledmulti-channel including plural channels is constituted by the forwardchannels and the backward channels.

Thus, audio signals of the forward channels, i.e., 2 channels from theforward microphones 12, 13 are delivered to the first speech processingsection 16. The first speech processing section 16 samples these audiosignals of the forward channels, e.g., at a sampling frequency of 44.1kHz prescribed (specified) by the CD-DA format thereafter to implement16 bit linear quantization thereto to deliver quantized data to therecording section 18. The recording section 18 records the quantizeddata thus delivered into the first recording area 3 of the first session9.

Audio signals of backward channels, i.e., 2 channels from backwardmicrophone 14, 15 are delivered to the second speech processing section17. The second speech processing section 17 similarly samples audiosignals of backward channels, e.g., at the sampling frequency of 44.1kHz to carry out compression by using, e.g., the algorithm of ATRAC(Adaptive Transform Acoustic Coding) to carry out bit compression intodata size of substantially 1/5 by exhibiting the auditory sensecharacteristic. The recording section 18 records this compressed datainto the second recording area 6 of the second session 10.

At this time, as described above, information frame in which the pointportion 112 is defined as, e.g., "B0" or "C0" and information frame inwhich the point portion 112 is defined as "E0" are recorded into thefirst management area 2, and information frame in which the pointportion 112 is defined as, e.g., "D1" is recorded into the secondmanagement area 5.

Meanwhile, in the conventional CD-DA format, digital audio informationof 4 channels can be recorded only by the time which is one half of therecordable time of the ordinary digital audio information of 2 channelsat the longest. To the contrary, the recording apparatus to which thisinvention is applied has improved the above-mentioned drawback, therebymaking it possible to realize a recording medium which is capable ofcarrying out long time recording of digital audio information ofmulti-channel represented by the digital audio information of 4 channelsand is capable of reproducing digital audio information recorded by theCD-DA format.

It is to be noted that explanation has been given in connection with theactual example (embodiment) in which, as discrimination data indicatingCD-R disc such that digital audio information of the CD-DA format whichcan be reproduced by the ordinary CD player is recorded in the firstsession 9, and digital audio information sampled at the samplingfrequency of 44.1 kHz and compressed by using the algorithm of ATRAC isrecorded in the second session 10, information frame in which the pointportion 112 of the first management area 2 is "B0" or "C0" andinformation frame in which the point portion 112 thereof is "E0" areprovided, and information frame in which the point portion 112 of thesecond management area 5 is "D1" is provided, this invention is notlimited to such embodiment. For example, other values may be recorded inthe point portion 112 of the first management area 2 and the pointportion 112 of the second management area 5 so that discrimination dataare provided.

In addition, while, in the above-described embodiment, audio signals ofthe backward channels are compressed by using the algorithm of ATRAC inthe second speech processing section 17, such audio signals may becompressed by using other compression algorithm without being limited tothe above-mentioned compression method. Further, an approach may beemployed, in place of compression, to carry out down-sampling so as toreduce the number of bits to carry out quantization so that data of theCD-ROM format is provided.

A second embodiment of the recording apparatus to which this inventionis applied will now be described.

The recording apparatus of the second embodiment includes, as shown inFIG. 8, for example, as the speech processing section 23, a quantizingsection 24 for sampling an audio signal from a sound source at apredetermined sampling frequency and for quantizing digital audioinformation thus obtained by a predetermined number of bits, and aseparating section 25 for separating the digital audio information fromthe quantizing section 24 into digital audio information of high orderbits and low order bits. In addition, the recording section 18 recordsthe digital audio information of the high order bits into the firstsession 9 of the CD-R disc 1, and records the digital audio informationof the low order bits into the second session 10 of the CD-R disc 1.

In more practical sense, audio signals from a first microphone 21 and asecond microphone 22 are delivered to the quantizing section 24. Thequantizing section 24 samples these audio signals, e.g., at the samplingfrequency of 44.1 kHz prescribed (specified) by the CD-DA formatthereafter to implement 20 bit linear quantization thereto. In thiscase, since the data size prescribed (specified) by the CD-DA format is16 bits, the separating section 25 separates the audio signal which hasbeen caused to undergo 20 bit quantization into data of high order 16bits and data of low order 4 bits.

The recording section 18 records the data of the high order 16 bitsseparated at the separating section 25 into the first recording area 3of the first session 9, and records the data of the low order 4 bitsinto the second management area 5 of the second session 10.

At this time, as described above, information frame in which the pointportion 112 is defined as, e.g., "B0" or "C0" and information frame inwhich the point portion 112 is defined as "E0" are recorded in the firstmanagement area 2, and information frame in which the point portion 112is defined as, e.g., "D2" is recorded in the second management area 5.

Meanwhile, in the conventional CD-DA format, since digital audioinformation quantized by the number of bits more than 16 bits or digitalaudio information having data size more than 16 bits cannot be directlyrecorded onto the disc, processing to reduce data size of such digitalaudio information is carried out to record the data thus processed ontothe disc as data of the CD-DA format. To the contrary, in the recordingapparatus to which this invention is applied, digital audio informationhaving data size of, e.g., 20 bits is divided into information of thehigh order 4 bits and the low order 4 bits to record digital audioinformation having data size of 16 bits of the high order bit side intothe first recording area 3 by the CD-DA format, and to record digitalaudio information of the remaining 4 bits of the low order bit side intothe second recording area 6, thereby making it possible to recorddigital audio information of 20 bits of which number of bits has beenincreased onto the CD-R disc. In addition, it is possible to reproduce,from the CD-R disc recorded in this way, digital audio informationrecorded by the CD-DA format by using the ordinary CD player.

It is to be noted that explanation has been given in connection with theactual example (embodiment) in which, as discrimination data indicatingCD-R disc such that digital audio information of which number of bitshas been increased is separated into digital audio information of highorder bits and low order bits to record respective digital audioinformation into the first recording area 3 and the second recordingarea 6, information unit in which the point portion 112 of the firstmanagement area 2 is "B0" or "C0" and information frame in which thepoint portion 112 is "E0" are provided, and information frame in whichthe point portion 112 of the second management area 5 is "D2" isprovided, this invention is not limited to this embodiment. For example,other values may be recorded in the point portion 112 of the firstmanagement area 2 and the point portion 112 of the second managementarea 5 so that discrimination data are provided.

Moreover, while, in the above-described embodiment, as a method ofseparating digital audio information of which number of bits has beenincreased into high order bits and low order bits, the example of simplycarrying out separation into high order 16 bits and low order 4 bits hasbeen taken, this invention is not limited to such embodiment. Forexample, data of the higher order bit side may be caused to be dataobtained on the basis of digital audio information of which number ofbits has been increased, and data of the low order bit side may becaused to be data obtained on the basis of the remaining data.

The configuration of a modified example of the recording apparatusadapted for recording digital audio information of which number of bitshas been increased in the state separated into high order bits and loworder bits is shown in FIG. 9.

In the recording apparatus of this modified example, in place of outputof the quantizing section 24, there is used digital audio informationobtained by reproducing a master tape 30 on which there is recordeddigital audio information quantized, e.g., by the number of bits morethan 16 bits after undergone sampling at a sampling frequency of 44.1kHz. Moreover, management information for carrying out management ofrecorded digital audio information is assumed to be written in above onthe master tape 30.

Further, in this recording apparatus, data of high order bits, e.g.,data of high order 16 bits to be recorded onto the CD-R disc 1 isassumed to be obtained by reducing the data size of the digital audioinformation from the master tape 30 to 16 bit data at a noise shapingsection 31 or a dither circuit section 32, and data of the low orderbits is caused to be difference between digital audio information fromthe master tape 30 and output from the noise shaping section 31 or thedither circuit section 32 at a difference calculating section 35.

Namely, the noise shaping section 31 carries out the so-calledoversampling of digital audio information from the master tape 30 inview of the auditory sense characteristic to thereby shift the frequencycharacteristic of noise to the side of the higher frequency band wheresensitivity is poor to lessen quantizing noise, and to allow digitalaudio information having the number of bits more than 16 bits to bedigital audio information of 16 bits (hereinafter simply referred to as16 bit data as the occasion may demand) by using the algorithm of theso-called sign bit mapping. Then, the noise shaping section 31 deliversthe 16 bit data to a management information generating section 42, anddelivers it to a music CD format converting section 36 and thedifference calculating section 35 through a 16 bit data path 33.

On the other hand, the dither circuit section 32 adds random noisesmaller than one quantization step a so-called dither to the digitalaudio information from the master tape 30 to convert data of the datasize greater than 16 bits into 16 bit data. For example, in convertingdata quantized at the quantization level of 20 bits, i.e., 20 bit datainto 16 bit data, since the step of one quantization level of 20 bits issmaller than one quantization step at the quantization level of 16 bits,data dispersed (distributed) between certain quantization steps of 16bits are statistically dispersed (distributed) at quantization levels of16 bits before and after to lessen quantizing noise. Then, the dithercircuit section 32 delivers this 16 bit data to the managementinformation generating section 42, and delivers it to the differencecalculating section 35 and the music CD format converting section 36through the 16 bit data path 33.

A timing correction memory 34 temporarily stores digital audioinformation having the number of bits more than 16 bits from the mastertape 30, and delivers the stored digital audio information to thedifference calculating section 35 in a manner synchronized with thetiming at which corresponding data is delivered from the noise shapingsection 31 or the dither circuit section 32 to the differencecalculating section 35.

The difference calculating section 35 takes difference between 16 bitdata from the noise shaping section 31 or the dither circuit section 32and data of size more than 16 bits from the timing correction memory 34to deliver difference data thus obtained to a mixing section 39.

The mixing section 39 mixes address data delivered from an address dataoutput section 37 and difference data from the difference calculatingsection 35 to generate set of data, i.e., mixed data. It is to be notedthat the address data indicates address on the CD-R disc 1 of 16 bitdata corresponding to the difference data, and is used for reproducingthe difference data and the 16 bit data in a manner synchronous witheach other at reproducing apparatus which will be described later. Then,the mixed data is delivered to an internal memory 41, and is temporarilystored thereinto.

On the other hand, the music CD format converting section 36 converts 16bit data into data prescribed (specified) by the CD-DA format to delivermusic CD format data thus obtained to an EFM section 45 through aselector (changeover) switch 40.

Moreover, a CD-ROM format converting section 38 converts mixed datastored in the internal memory 41 into data prescribed (specified) by theCD-ROM format to deliver CD-ROM format data thus obtained to the EFMsection 45 through the selector switch 40.

The management information generating section 42 includes register, andgenerates management data for forming management information to berecorded into the first management area 2 or the second management area5 on the basis of the management information reproduced from the mastertape 30 and output from the noise shaping section 31 or the dithercircuit section 32 to temporarily stores it into the register. Moreover,the management information generating section 42 delivers the managementdata stored in the register to the EFM section 45 through the selectorswitch 40. As described later, after first management data to berecorded into the first management area 2 is outputted to the EFMsection 45, second management data to be recorded into the secondmanagement area 5 is generated, and the second management data thusgenerated is stored into the register.

A lead-out generating section 43 generates lead-out data to be recordedinto the first lead-out area 4 and the second lead-out area 7 to outputit to the EFM section 45 through the selector switch 40.

The control section 44 controls switching operation of the selectorswitch 40. In this case, data recording onto the CD-R disc 1 is carriedout in order from the inner circumferential side, i.e., in order of thefirst management area 2, the first recording area 3, the first lead-outarea 4, the second management area 5, the second recording area 6 andthe second lead-out area 7.

Accordingly, the control section 44 switches the selector switch 40 inaccordance with the order recorded onto the CD-R disc 1 so that outputof the management information generating section 42 is selected at thetime of start of recording to deliver the first management data to theEFM section 45 to subsequently switch the selector switch 40 so thatoutput of the music CD format converting section 36 is selected todeliver music CD format data to be recorded into the first recordingarea 3, which is sent on the real time basis, to the EFM section 45 tofurther switch the selector switch 40 so that output of the lead-outgenerating section 43 is selected to deliver first lead-out data to berecorded into the first lead-out area 4 to the EFM section 45. Further,the control section 44 sends out data to be recorded into the firstsession 9 to the EFM section 45 thereafter to carry out, also withrespect to data to be recorded into the second session 10, a control forswitching the selector switch 40 in order of the management informationgenerating section 42, the CD-ROM format converting section 38 and thelead-out generating section 43 to deliver data thus obtained to the EFMsection 45. In this example, the CD-ROM format converting section 38 isoperative so that when its output is selected by the selector switch 40,it takes out data stored in the internal memory 41 to convert it intodata of the CD-ROM format to output it.

The EFM section 45 modulates data delivered through the selector switch40 from respective circuit components by the algorithm of EFM (Eight toFourteen Modulation) which is the modulation system employed in the CDsystem to convert data inputted thereto into data in a form suitable forbeing written onto the CD-R disc 1 to output it to a laser diode 46.

The laser diode 46 is a recording light source for recording dataoutputted from the EFM section 45 onto the CD-R disc 1, and serves toemit recording laser beams in accordance with data from the EFM section45 to irradiate these recording laser beams onto the recording surfaceprovided on the surface of the CD-R disc 1 to carry out recording.

It is to be noted that, as shown in FIG. 10, for example, a detectingsection 48 may be further provided to detect, at this detecting section48, respective data quantities of the music CD format data and theCD-ROM format data to discriminate on the basis of the detection resultwhether or not insufficiency takes place in the second recording area 6into which CD-ROM format data will be written later to allow the controlsection 51 to be operative in accordance with the discrimination result.

Namely, the discrimination result is a signal generated in the casewhere when recording into the first recording area of the music CDformat data is still more continued, the possibility that the secondrecording area 6 for recording the CD-ROM format data corresponding tothe music CD format data may become insufficient takes place. Thissignal is delivered to the control section 51. Then, the control section51 controls the selector switch 40 on the basis of this signal. Inaddition, the discrimination result is delivered to an alarm displaysection 49 to allow it to carry out display notifying compulsory end ofrecording of the first recording area.

Moreover, as shown in FIGS. 11A-11C for example, there may be employed aconfiguration in which there are provided a time code output section 52for outputting time code in order to link 16 bit data and differencedata similarly to the address data, and a time code data convertingsection 53 for converting time code from the time code output section 52into data for mixing it with difference data from the differencecalculating section 35 to record data including time code informationinto the second recording area 6 of the CD-R disc 1.

Namely, in FIG. 11C, a music CD format converting section 55 converts 16bit data delivered through the 16 bit data path 33 from the noiseshaping section 31 or the dither circuit section 32 into music CD formatdata. Then, this music CD format data is caused to undergo EFM. The datathus obtained is recorded into respective areas of the first session 9by using recording light source such as laser diode, etc.

On the other hand, a mixing section 54 mixes difference data from thedifference calculating section 35, time code data from the time codedata converting section 53, and address data from the address dataoutput section 37 to deliver mixed data thus obtained to a CD-ROM formatconverting section 56. The CD-ROM format converting section 56 convertsthis mixed data into CD-ROM format data. The CD-ROM format data thusobtained is subjected to EFM. The data thus modulated is then recordedinto respective areas of the second session 10 by using recording lightsource such as laser diode, etc.

Moreover, in the recording apparatus shown in FIG. 11C, recording intothe first session 9 by the music CD format converting section 55 andrecording into the second session 10 by the CD-ROM format convertingsection 56 are carried out by using recording heads independentrespectively. Accordingly, the internal memory 41 provided in therecording apparatus shown in FIGS. 9 and 10 becomes unnecessary. In thisrecording apparatus, mixed data outputted from the mixing section 54 isdirectly delivered to the CD-ROM format converting section 56.

It is to be noted that, also in the recording apparatus shown in FIGS. 9and 10, the circuit section for outputting data relating to time codelike the time code output section 52 of the recording apparatus shown inFIG. 11C may be provided to output time code data to the mixing section54. In other words, in the recording apparatus shown in FIG. 11C,similarly to the recording apparatus shown in FIGS. 9 and 10, singlerecording head may be used to record time code, etc. into the secondrecording area 6.

A third embodiment of the recording apparatus to which this invention isapplied will now be described.

The recording apparatus of the third embodiment includes, as shown inFIG. 12, for example, quantizing section 24 for sampling an audio signalfrom a sound source for recording at a predetermined sampling frequencyand for quantizing digital audio information thus obtained by apredetermined number of bits, and a (frequency) band dividing section 61for band-dividing digital audio information from the quantizing section24 at a frequency which is 1/n (n is integer) of the predeterminedsampling frequency so that dividing into two groups is carried out. Inthis case, the recording section 18 records digital audio information ofone group of two groups into the first session 9 of the CD-R disc 1, andrecords digital audio information of the other group into the secondsession 10 of the CD-R disc 1.

In more practical sense, audio signals from a first microphone 21 and asecond microphone 22 are delivered to the quantizing section 24. Thequantizing section 24 samples these audio signals at a samplingfrequency, e.g., 88.2 kHz which is higher than the sampling frequencyprescribed (specified) by, e.g., the CD-DA format thereafter toimplement 20 bit linear quantization thereto. In this case, the datasize prescribed (specified) by the CD-DA format is 16 bits sampled at asampling frequency of 44.1 kHz. In addition, the valid (effective)signal component in the digital audio information sampled by apredetermined sampling frequency is the signal component at the lowerfrequency band side with respect to the frequency which is one half ofthe sampling frequency.

In view of the above, the band dividing section 61 is composed of, e.g.,low-pass filter for allowing the signal component less than 22 kHz to bepassed therethrough, and a band pass filter for allowing the signalcomponent of the band of 22 kHz˜44 kHz to be passed therethrough. Theband dividing section 61 takes out, by the low-pass filter, the signalcomponent less than 22 kHz of digital audio information sampled at thesampling frequency of 88.2 kHz to deliver this signal component to afrequency characteristic converting section 62, and takes the signalcomponent of 22 kHz˜44 kHz by the band pass filter to deliver thissignal component to a compression processing section 63.

The frequency characteristic converting section 62 further samples thesignal component of the band up to 22 kHz at the sampling frequency of44.1 kHz to reduce the data size of 20 bits into 16 bits by using, e.g.,the above-described algorithm of the sign bit mapping to deliver it tothe recording section 18. In this way, data prescribed (specified) bythe CD-DA format, i.e., data sampled at the sampling frequency of 44.1kHz and quantized by 16 bits is obtained.

On the other hand, the compression processing section 63 compresses thesignal component of the band of 22 kHz˜44 kHz into data of data size ofsubstantially 1/5 by using, e.g., the above-described algorithm of ATRACto deliver it to the recording section 18.

The recording section 18 records data from the frequency characteristicconverting section 62 into the first recording area 3 of the firstsession 9 of the CD-R disc 1 to convert the compressed data from thecompression processing section 63 into data of the CD-ROM format torecord it into the second recording area 6 of the second session 10 ofthe CD-R disc 1.

At this time, as described above, information frame in which the pointportion 112 is defined as, e.g. , "B0" or "C0" and information frame inwhich the point portion 112 is defined as "E0" are recorded into thefirst management area 2, and information frame in which, e.g., the pointportion 112 is defined as "D3" is recorded into the second managementarea 5.

Meanwhile, in the case of the conventional CD-DA format, it wasimpossible to directly carry out recording of digital audio informationsampled by a sampling frequency higher than 44.1 kHz. On the contrary,in the case of the recording apparatus to which this invention isapplied, it is possible to prepare (produce) a CD-R disc where digitalaudio information of the CD-DA format of which number of bits has beenreduced by down-sampling the signal component of the lower frequencyband side of digital audio information sampled by a sampling frequencyof, e.g., 88.2 kHz is recorded in the first recording area and digitalaudio information obtained by compressing the signal component of thehigher frequency band side is recorded in the second recording area 6.In addition, it is possible to reproduce, from the CD-R disc thusrecorded, digital audio information recorded by the CD-DA format byusing the ordinary CD player.

Moreover, in the conventional CD-DA format, it was impossible todirectly carry out recording of digital audio information quantized bythe number of bits more than 16 bits or digital audio information havingdata size more than 16 bits. On the contrary, in the recording apparatusof the third embodiment, an approach is employed to divide, e.g.,digital audio information having data size of 20 bits into digital audioinformation of the lower frequency band side and digital audioinformation of the higher frequency band side to reduce the number ofbits of the digital audio information of the lower frequency band sideby the sign bit mapping, etc., and to compress the digital audioinformation of the higher frequency band side, thereby making itpossible to realize a recording medium which is capable of recordingdigital audio information of which number of bits has been increased,and is capable of reproducing digital audio information recorded by theCD-DA format by using the ordinary CD player similarly to the recordingapparatus of the second embodiment.

It is to be noted that while explanation has been given in connectionwith the more practical example where, as discrimination data indicatingCD-R disc in which digital audio information which has been caused toundergo the so called high-sampling where the sampling frequency iscaused to be higher than 44.1 kHz is band-divided at a predeterminedfrequency, and data of the lower frequency band side thus obtained isrecorded into the first recording area 3 after undergone down-samplingat a sampling frequency of 44.1 kHz and the data of the higher frequencyband side is recorded into the second recording area 6 after undergonecompression by using the algorithm of ATRAC, information frame in whichthe point portion 112 of the first management area 2 is "B0" or "C0",and information frame in which the point portion 112 is "E0" areprovided, and information frame in which the point portion 112 of thesecond management area 5 is "D3" is provided. However, this invention isnot limited to this actual example. For example, other values may berecorded into the point portion 112 of the first management area 2 andthe point portion 112 of the second management area 5 so thatdiscrimination data are provided.

In addition, while the signal component of the higher frequency bandside is compressed by using the algorithm of ATRAC at the compressionprocessing section 63 in the above-described embodiment, this inventionis not such implementation. Any other compression algorithm may be usedto carry out compression. Further, down-sampling may be carried out soas to reduce the number of bits in place of compression to carry out aquantization such that data of the CD-ROM format is provided.

A first embodiment of a reproducing apparatus to which this invention isapplied will now be described.

The reproducing apparatus of the first embodiment is directed to areproducing apparatus adapted for reproducing digital audio informationfrom CD-R disc 1 including, as shown in FIGS. 1A-1B, for example, firstrecording area 3 where digital audio information is recorded, firstmanagement area 2 where information for carrying out management of thedigital audio information recorded in the first recording area isrecorded, second recording area 6 where digital audio informationcorresponding to the digital audio information recorded in the firstrecording area 3 is recorded, and second management area 5 whereinformation for carrying out management of the digital audio informationrecorded in the second recording area 6 is recorded, the apparatuscomprising, as shown in FIG. 13, an optical pick-up 70 and a signalprocessing section 71 for reproducing digital audio information from theCD-R disc 1, a first memory 72 for storing the digital audio informationwhich has been read from the first recording area 3 by the opticalpick-up 70, a second memory 73 for storing the digital audio informationwhich has been read from the second recording area 6 by the opticalpick-up 70, a first discriminating section 74 for discriminating whetheror not quantity of data stored in the first memory 72 is a predeterminedquantity or more, a second discriminating section 75 for discriminatingwhether or not quantity of data stored in the second memory 73 is apredetermined quantity or more, a servo circuit section 77 for movingthe optical pick-up 70, and a control section 76 for conducting acontrol to move the optical pick-up 70 to the second recording area 6 onthe basis of information of the first management area 2 to store thedigital audio information which has been read from the second recordingarea 6 into the memory 73, whereby in the case where it is discriminatedat the second discriminating section 75 that quantity of data stored inthe second memory 73 is the predetermined quantity or more, the controlsection 76 moves the optical pick-up 70 to the first recording areawhere digital audio information corresponding to the digital audioinformation stored in the second memory 73 is recorded to store thedigital audio information which has been read from the first recordingarea 3 into the first memory 72 to output digital audio information fromthe first memory 72 and the second memory 73 while takingsynchronization therebetween.

In this case, as described above, the CD-R disc 1 is an optical disc ofthe multisession (type) such that data of the CD-DA format is recordedin the first session 9 including the first management area 2 and thefirst recording area 3, and data of the CD-ROM format is recorded in thesecond session 10 including the second management area 5 and the secondrecording area 6.

In operation, the optical pick-up 70 reads out data from the CD-R disc 1to deliver a reproduction signal thus obtained to the signal processingsection 71. Moreover, the optical pick-up 70 provides access to thefirst recording area 3 or the second recording area 6 on the basis of aservo control signal from servo circuit section 77 which will bedescribed later. In this case, the access time from the first session 9to the second session 10 of the CD-R disc 1 and the access time of theoptical pick-up 70 from the second session 10 to the first session 9are, e.g., 1 second.

The signal processing section 71 extracts, from the reproduction signal,discrimination data indicating kind (type) of the CD-R disc 1 obtainedfrom the first management area 2 or the second management area 5 todeliver it to the control section 76. Then, the control section 76controls the signal processing section 71, etc. on the basis of thediscrimination data. In more practical sense, the signal processingsection 71 implements signal processing for the CD-DA format to areproduction signal obtained by reading out the first session 9 undercontrol of the control section 76 to deliver digital audio informationthus obtained to the first memory 72, and implements a predeterminedsignal processing to a reproduction signal obtained by reading out thesecond session 10 to deliver digital audio information thus obtained tothe second memory 73.

For example, in the case where the CD-R disc 1 recorded at the recordingapparatus of the first embodiment is reproduced as described later, CD-Rdisc 1 to be reproduced is a disc including the second session 10,wherein data recorded in the second recording area 6 is data compressedby using the algorithm of ATRAC, and information frame in which thepoint portion 112 is "B0" or "C0" is recorded in the management area 2and information frame in which the point portion 112 is "D1" is recordedin the second management area 5. When the signal processing section 71detects these information frames, it delivers discrimination data fordiscriminating between the information frames to the control section 76.The control section 76 controls the signal processing section 71 by acontrol signal corresponding to the discrimination data, and the signalprocessing section 71 expands data corresponding to the second recordingarea 6 to deliver digital audio information thus obtained to the secondmemory 73.

The first memory 72 temporarily stores digital audio informationcorresponding to the first recording area 3 delivered from the signalprocessing section 71. Moreover, this first memory 72 delivers dataindicating storage data quantity thus taken to the first discriminatingsection 74, and reads out the digital audio information stored thereinon the basis of a memory control signal from the control section 76 todeliver it to a reproduction output section 79. Moreover, the secondmemory 73 temporarily stores digital audio information corresponding tothe second recording area 6 from the signal processing section 71.Further, similarly to the first memory 72, the second memory 73 deliversdata indicating storage data quantity thus taken to the seconddiscriminating section 75, and reads out the digital audio informationstored therein on the basis of a memory control signal from the controlsection 76 to deliver it to the reproduction output section 79.

Namely, the first discriminating section 74 discriminates on the basisof data indicating storage data quantity sent from the first memory 72whether or not storage data quantity of the first memory 72 reaches apredetermined quantity, e.g., storage allowed quantity to deliverdiscrimination data indicating the discrimination result to the controlsection 76. Similarly, the second discriminating section 75discriminates on the basis of data indicating storage data quantity sentfrom the second memory 73 whether or not storage data quantity of thesecond memory 73 reaches a predetermined quantity, e.g., storage allowedquantity to deliver discrimination data indicating the discriminationresult to the control section 76. It is to be noted that while the firstand second discriminating sections 74, 75 are provided independent ofthe first and second memories 72, 73 in this example, these sections maybe provided within the respective memories 72, 73 or within the controlsection 76.

Explanation will be given with reference to the flowchart shown in FIG.14, for example, in connection with the operation of the reproducingapparatus of the first embodiment, i.e., the reproducing method to whichthis invention is applied.

The reproducing method to which this invention is applied is areproducing method for reproducing digital audio information from arecording medium including a first recording area 3 where digital audioinformation is recorded, a first management area 2 where information forcarrying out management of the digital audio information recorded in thefirst recording area 3 is recorded, a second recording area 6 wheredigital audio information corresponding to the digital audio informationrecorded in the first recording area 3 is recorded, and a secondmanagement area 5 where information for carrying out management of thedigital audio information recorded in the second recording area 6 isrecorded, the method includes, as shown in FIG. 14, steps S1, S2 ofreading information of the first management area 2 to discriminate onthe basis of the management information thus read whether or not thesecond recording area 6 exists, step S6 such that in the case where itis discriminated at the steps S1, S2 that the second recording area 6exists, the optical pick-up 70 is caused to be moved to the secondmanagement area 5, steps S12, S13, S14 of reading information of thesecond management area 5 by the optical pick-up 70 which has been movedat the step S6 to read the digital audio information of the secondrecording area 6 on the basis of the information thus read to store thedigital audio information which has been read into the first memory 72,step S15 of moving the optical pick-up 70 to the data recording positionwithin the first recording area 3 where digital audio informationcorresponding to the digital audio information from the second recordingarea 6 stored in the first memory 72 at the steps S12 to S14 isrecorded, and steps S16, S17 of reading out digital audio information ofthe first recording area 3 by the optical pick-up 70 moved at the stepS15 to store the digital audio information thus read out to the secondmemory 73, and to output the digital audio information stored in thefirst memory 72 and the second memory 73 while taking synchronizationtherebetween.

Further, this reproducing method includes step S18 of comparing storagequantity of the second memory and a predetermined value, and step S20such that in the case where it is discriminated at the step S18 thatstorage quantity of the second memory is the predetermined value ormore, a procedure is taken to move the optical pick-up 70 to the datarecording position within the second recording area 6 where digitalaudio information successive (continuous) to the digital audioinformation stored in the first memory 72 is recorded, and to read outthe digital audio information, and steps S21, S22 of storing the digitalaudio information of the second recording area 6 which has been read atthe step S20 into the first memory 72, and to output the digital audioinformation stored in the first memory 72 and the digital audioinformation stored in the second memory 73 while taking synchronizationtherebetween.

In this reproducing method, at step S0, reproduction operation of theCD-R disc 1 is started. At step S1, the optical pick-up 70 providesaccess to the first management area 2 to reproduce information. Namely,the control section 76 delivers a servo circuit control signal to theservo circuit section 77 to control the access operation of the opticalpick-up 70.

At step S2, whether or not information frame in which data PO shown inFIG. 5 is "B0" exists within management information (hereinafterreferred to as first management information) delivered from the opticalpick-up 70 is discriminated at the control section 76. Namely, whetheror not a disc being reproduced is multi-session disc is a discriminated.In the case where the discrimination result is NO, i.e., the disc beingreproduced is the single session disc, the processing proceeds to stepS3. Thus, the reproducing apparatus carries out reproduction processingof the ordinary disc.

On the other hand, in the case where the discrimination result at thestep S2 is YES, i.e., the disc being reproduced is discriminated to be amultisession disc, the processing proceeds to step S4. Whether or notinformation frame in which data PO is "E0" exists within the firstmanagement information is discriminated in turn at the control section76. When this discrimination result is NO, i.e., the disc beingreproduced is discriminated to be a disc such that only character datais recorded in the second management area 5 of the second session 10,and no data is recorded in the second recording area 6, the processingproceeds to step S5. Thus, the reproducing apparatus carries outreproduction processing of the so-called disc with character.

Moreover, in the case where the discrimination result at the step S4 isYES, i.e., the disc being reproduced is discriminated to be a CD-R disc,the processing proceeds to step S6. Thus, the optical pick-up 70provides access to the second management area 5 on the basis of addressinformation indicated in the first management information. Namely, thecontrol section 76 delivers a servo circuit control signal to the servocircuit section 77 to control the access operation of the opticalpick-up 70.

At step S7, the optical pick-up 70 carries out reproduction of thesecond management area 5. Then, the processing proceeds to step 58.

At the step S8, the control section 76 stores, into the internal memory,the data content of the second management area 5 (hereinafter referredto as second management information). Then, the processing proceeds tostep S9. Thus, the reproducing apparatus is placed in the command inputwaiting state, and once becomes inoperative.

At step S10, when the control section 76 discriminates that there iscommand input, the processing proceeds to step S11. Thus, the controlsection 76 releases the temporary stop. Then, the processing proceeds tostep S12.

At the step S12, the control section 76 delivers a servo circuit controlsignal to the servo circuit section 77 on the basis of addressinformation of the second management information. The optical pick-up 70provides access to the second recording area 6.

At step S13, the signal processing section 71 carries out scramblerelease processing for CD-ROM format of the second recording area 6recorded by the standard of the CD-ROM and/or CD-ROM processing, e.g.,error correction or address processing, etc. Namely, the control section76 sends, to the signal processing section 71, a control signal forallowing it to carry out processing.

At step S14, the second memory 73 takes thereinto reproduction dataobtained by the CD-ROM processing. Namely, the control section 76delivers a processing control signal to the signal processing section 71and delivers a memory control signal to the second memory 73.

At step S15, the optical pick-up 70 provides access to the firstrecording area 3 on the basis of address where digital audio informationcorresponding to the reproduction data taken into second memory 73 isrecorded. Namely, the control section 76 delivers a servo circuitcontrol signal to the servo circuit section 77 to control the accessoperation of the optical pick-up 70.

At step S16, the optical pick-up 70 reproduces reproduction data fromthe first recording area 3 accessed at the step S15 to output it.Further, the first memory 72 takes this reproduction data thereinto.Namely, the control section 76 delivers, to the signal processingsection 71, a processing control signal for allowing it to carry outprocessing, and delivers a memory control signal to the first memory 72.

At step S17, the first memory 72 and the second memory 73 read outdigital audio information stored therein every predetermined dataquantity to deliver them to the reproduction output section 79. Thereproduction output section 79 mixes digital audio information deliveredthereto to output it. Namely, the control section 76 delivers a memorycontrol signal to the first memory 72 and the second memory 73, anddelivers a reproduction control signal to the reproduction outputsection 79. It is to be noted that, also for this time period,reproduction data obtained by reproducing the first recording area issent from the signal processing section to the first memory 72, and isstored thereinto.

At the step S18, the control section 76 discriminates whether or not thefirst memory 72 reaches a data storage allowed quantity. When thisdiscrimination result is NO, i.e., it is discriminated that a space areaexists in the first memory 72, the processing proceeds to step S19.

At the step S19, the optical pick-up 70 continues reproduction of thefirst recording area 3, and the first memory 72 stores reproduction datafrom the optical pick-up 70. Namely, the control section 76 delivers aservo circuit control signal to the servo circuit section 77 to controlthe access operation of the optical pick-up 70, delivers a processingcontrol signal to the signal processing section 71, and delivers amemory control signal to the first memory 72. Then, the processingreturns to the step S17.

On the other hand, when the discrimination result at the step S18 isYES, i.e., the control section 76 discriminates that the first memory 72has reached the data storage allowed quantity, the processing proceedsto step S20.

At the step S20, the optical pick-up 70 provides access to successiveaddress of the second recording area 6 to reproduce data. Namely, thecontrol section 76 delivers a servo circuit control signal to the servocircuit section 77 to control the access operation of the opticalpick-up 70.

At step S21, the second memory 73 takes thereinto reproduction data ofthe second recording area 6 reproduced by the optical pick-up 70 at thestep S20. Namely, the control section 76 delivers a processing controlsignal to the signal processing section 71 and delivers a memory controlsignal to the second memory 73.

At step S22, the first memory 72 and the second memory 73 read outstored digital audio information every predetermined data quantity todeliver them to the reproduction output section 79. The reproductionoutput section 79 mixes the digital audio information delivered theretoto output it. Then, the control section 76 delivers a memory controlsignal to the first memory 72 and the second memory 73, and delivers areproduction control signal to the reproduction output section 79. It isto be noted that, also for this time period, reproduction data obtainedby reproducing the second recording area 6 is sent from the signalprocessing section 71 to the second memory 73, and is stored thereinto.

At step S23, the control section 76 discriminates whether or not thesecond memory 73 reaches the data storage allowed quantity. When thisdiscrimination result is NO, i.e., it is discriminated that any spacearea exists in the second memory 73, the processing returns to the stepS21. In contrast, when the discrimination result is YES, i.e., it isdiscriminated that the memory 73 has reached the data storage allowedquantity, the processing proceeds to step S24.

At the step S24, the optical pick-up 70 provides access to successiveaddress of the first recording area 3 to reproduce data. Namely, thecontrol section 76 delivers a servo circuit control signal to the servocircuit section 77 to control the access operation of the opticalpick-up 70.

At step S25, the discriminating section 76 discriminates whether or notreproduction of the first recording area 3 is completed, or whether ornot command input for stop operation is given. When this discriminationresult is NO, i.e., it is discriminated that digital audio informationwhich has not been yet reproduced exists in the first recording area 3,and it is discriminated that there is no command input for stopoperation, the processing proceeds to step S26.

At the step S26, the optical pick-up 70 continues reproduction of thefirst recording area 3, and the first memory 72 stores reproduction datafrom the optical pick-up 70. Namely, the control section 76 delivers aservo circuit control signal to the servo circuit section 77 to controlthe access operation of the optical pick-up 70, delivers a processingcontrol signal to the signal processing section 71, and delivers amemory control signal to the first memory 72. Then, the processingreturns to the step S17.

On the other hand, in the case where discrimination result is YES, i.e.,it is discriminated that reproduction of the digital audio informationof the first recording area 3 is completed, or command input for stopoperation is given, the processing proceeds to step S27. Thus, thisreproducing apparatus completes the reproducing operation.

It is to be noted that in the case where in the case of CD-R disc inwhich time code is added in the second recording area 6 by the CD-ROMformat, at the step S17 and the step S22, even if an approach is notemployed to take out reproduction data from the first memory 72 andreproduction data from the second memory 73 by allowing timings to be incorrespondence with each other, data of the first memory 72 and thesecond memory 73 are read out at the same time (in parallel), therebymaking it possible to output digital audio information in a mannercaused to be synchronous with each other.

In a reproducing method as shown in FIG. 14, in order to temporarilytake data which has been read into the memory to output data from thememory, it is the necessary condition that the data write speed inwriting data into the memory is more than the data read speed.

In view of the above, it is necessary that the speed for writing digitalaudio information into the first memory 72 is higher than the speed forreading out digital audio information from the first memory, and thespeed for writing digital audio information into the second memory 73 ishigher than the speed for reading out digital audio information from thesecond memory.

Explanation will be given in connection with the write speed and theread speed with respect to the first memory 72 and the write speed andread speed with respect to the second memory 73 by taking the example ofa reproducing method for reproducing CD-R disc where CD-DA format datais recorded in the first recording area 3 and compressed data compressedby using the algorithm of ATRAC is recorded in the second recording area6.

The data read speed (rate) at the time of reproduction prescribed in theordinary CD system is 1.4112 M bits/sec. Moreover, since compressed datacompressed by using the algorithm of ATRAC as described above iscompressed into data of data size of substantially 1/5, the read speedof compressed data from the second memory 73 is 0.2822 (=1.4112×(1/5)) Mbits/sec.

In order to satisfy the condition as described above, since the dataread speed from the first memory 72 for taking thereinto digital audioinformation of the first recording area 3 at the time of reproduction is1.4112 (M bits/sec.), it is necessary that the data write speed into(with respect to) the first memory 72 is 1.4112 (M bits/sec.) or more.Moreover, since the data read speed from the second memory 73 for takingthereinto digital audio information of the second recording area 6 incarrying out reproduction in a manner synchronized with digital audioinformation of the first recording area 3 is 282.2 (=1.4112 (Mbits/sec.)×(1/5) K bits/sec., it is necessary that the data write speedinto (with respect to) the second memory 73 is 282.2 K bits/sec. ormore.

Explanation will be given on the premise that the data write speed into(with respect to) the first memory 72 (hereinafter referred to as firstwrite speed as the occasion may demand) is caused to be value four timesgreater (higher) than the data read speed from the first memory 72(hereinafter referred to as first read speed as the occasion maydemand), i.e., 5.6448 (M bits/sec.), and the write speed into (withrespect to) the second memory (hereinafter referred to as second writespeed as the occasion may demand) is caused to be value 20 times greater(higher) than the data read speed from the second memory 73 (hereinafterreferred to as second read speed as the occasion may demand), i.e.,5.6448 (M bits/sec.).

The first memory 72 stores data in order from address A₀, as shown inFIG. 15A, for example, to repeat such storage operation at a certainperiod. The second memory 73 stores data in order from address A₀similarly to the first memory 72, as shown in FIG. 15B, for example, torepeat such storage operation at a certain frequency. It is to be notedthat storage allowed quantities of data of the first memory 72 and thesecond memory 73 are respectively caused (assumed) to be 16.38 M bits.

Moreover, write vector W₁ is defined as vector indicating direction andaddress in writing data into the first memory 72 in order from A₀.Further, read vector R₁ is defined as vector indicating direction andaddress in reading data in order from address A₀ of the first memory 72.Furthermore, also with respect to the second memory 73, write vector W₂and read vector R₂ are similarly defined. In addition, when capacity ofthe memory is m, data write speed into the memory is w and data readspeed from the memory is r (w>r), the time T required until the memoryreaches the data storage allowed quantity is generally expressed by thefollowing formula (1).

    T=m/(w-r)                                                  (1)

In accordance with the above formula (1), the time T₁ required until thefirst memory 72 reaches the data storage allowed quantity is 3.8690(=16.38/(5.6448-1.4112) sec., i.e., approximately 3.9 sec. On the otherhand, the time T₂ required until the second memory 73 reaches the datastorage allowed quantity is 3.0545 (=16.38/(5.6448-0.2822)) sec., i.e.,approximately 3.1 sec.

Moreover, since the first write speed is the value four times greater(higher) than the first read speed, and the second write speed is thevalue 20 times greater (higher) than the second read speed, movement(advancing) speed of the write vector W₁ becomes equal to value fourtimes greater than the movement (advancing) speed of the read vector R₁,and the movement speed of the write vector W₂ becomes equal to value 20times greater than the movement speed of the read vector R₂.

The timing for taking out digital audio information from respectiverecording areas to reproduce them is shown in a model form in the timechart of FIG. 16.

In this time chart, after reproduction starts and the control section 76of the reproducing apparatus shown in FIG. 13 takes thereinto data ofthe first management area 2 and data of the second management area 5,the optical pick-up 70 provides access to the second recording area 6from the first recording area 3 on the basis of the data of the secondmanagement area 5 for the time period from the time t₀ the time t₁.

For the time period 11 from the time t₁ to the time t₂, the reproductiondata from the second recording area 6 is written into the second memory73. For the time period from the time t₂ to the time t₃, the opticalpick-up 70 provides access to the first recording area 3 from the secondrecording area 6.

Moreover, for the time period 12 from the time t₃ to the time t₄,reproduction data from the first recording area 3 is written into thefirst memory 72. For the time period from the time t₄ to the time t₅,the optical pick-up 70 provides access to the second recording area 6from the first recording area 3.

For the time period 13 from the time t₅ to the time t₆, reproductiondata from the second recording area 6 is written into the second memory73. For the time period from the time t₆ to the time t₇, the opticalpick-up 70 provides access to the first recording area 3 from the secondrecording area 6.

Moreover, for the time period 14 from the time t₇ to the time t₈,reproduction data from the first recording area 3 is written into thefirst memory 72. For the time period from the time t₈ to the time t₉,the optical pick-up 70 provides access to the second recording area 6from the first recording area 3.

In this example, it is assumed that the reproduction operation starts atthe time t₁ and reproduction data is actually outputted at the time t₃.

Further, the access time between the first recording area 3 and thesecond recording area 6 is 1 sec. as described above.

Furthermore, the time period l₁ is, e.g., 0.3 sec., and data is takeninto the second memory 73 from the second recording area 6 for this timeperiod l₁. In addition, since the write vector W₂ has speed 20 timesgreater than that of the read vector R₂, reproduction data of 6(=0.3×20) sec. is taken into the second memory 73. Namely, for 6 sec.from the time t₂, there is no necessity of taking data into the secondmemory 73 from the second recording area 6.

The time period l₂ starts after the time period l₅, i.e., 1.3 (=0.3+1)sec. Moreover, as described above, the time T₁ required until the firstmemory 72 reaches the data storage allowed quantity is 3.9 sec. For thistime period 12, data is taken into the first memory 72 from the firstrecording area 3. Further, since the write vector W₁ has speed fourtimes greater than that of the read vector R₁, reproduction data of 15.6(=3.9×4) sec. is taken into the first memory 72. At this time, sinceoutput of reproduction data from the first memory 72 starts from thestarting time of the time period 1₂ as described above, reproductiondata of 11.7 (=15.6-3.9) sec. remains in the first memory 72 at the timewhen data has been taken in, i.e., at the time t₄.

The time period l₃ starts after the time period I₆ from the time t₃,i.e., 4.9 (=3.9+1) sec. Moreover, the time T₂ required until the secondmemory 73 reaches the data storage allowed quantity is 3.1 sec. asdescribed above. For this time period l₃, data is taken into the secondmemory 73 from the second recording area 6. In this case, the time t₅when taking of data into the second memory 73 is started for a secondtime is passed by 5.9 (=1+4.9) sec. obtained by adding 1 sec. and thetime period l₆, i.e., 4.9 (=3.9+1) sec from the time t₂ when taking ofdata into the second memory 73 has been previously stopped. Since thiselapsed time is less than the above-described 6 sec., there is nopossibility that the second memory 73 may become empty for this timeperiod 1₆. It is to be noted that reproduction data of 62 (=3.1×20) sec.has been taken into the second memory 73 for the time period l₃, butsince the data read-out operation is continued, reproduction data of58.9 (=62-3.1) sec. remains in the second memory 73 at the time whentaking-in of data has been completed, i.e., at the time t₆.

Moreover, for the time period l₄, such an operation to once take datafor 3.9 sec. from the first recording area 3 into the first memory 72,and to twice output data for 15.6 sec. from the first memory 72 iscarried out. Namely, the time period l₄ is 35.1 (=15.6+15.6+3.9) sec. Inthis case, the time t₄ when taking of data into the first memory 72 isstarted for a second time is passed by the time period l₇, i.e., 5.1(=1+3.1+1) sec. from the time t₄ when taking of data into the firstmemory 72 has been previously stopped. However, since this elapsed timeis less than the above-described 11.7 sec., there is no possibility thatthe first memory 72 may become empty at this time period l₇. In thisexample, reproduction data of 11.7 sec. is taken into the first memory72 from the time when the time period l₇ is completed, i.e., the timet₈.

Further, taking of data into the second memory 73 is started from thetime t₉. In this case, since this time t₉ is passed by the time periodl₈, i.e., 37.1 (=1+35.1+1) sec. from the time when taking of data intothe second memory 73 has been previously stopped, i.e., the time t₆, butthis elapsed time is less than the above-described 58.9 sec., there isno possibility that the second memory 73 may become empty for this timeperiod l₈.

In a manner as described above, the operation of the time period l₉ fromthe time t₅ to the time t₉ is continued, thereby making it possible toreproduce data from the first recording area 3 and the second recordingarea 6 in the state where sound (speech) is not interrupted to outputthem in the state where synchronization is established. Namely, the timeperiod l₉ is 40.2 (=3.1+1+35.1+1) sec.

It is to be noted that while explanation has been given by taking, asthe disc to be reproduced, the example of the CD-R disc including pluralrecording areas, and such that data of the CD-DA format standard isrecorded in the first recording area 3, and data of the CD-ROM formatstandard is recorded into the second recording area 6, wherein datacompressed by using the algorithm of ATRAC is recorded as the data ofthe CD-ROM format standard, disc in other form as described later may beused.

Further, while the speed for writing data taken from the disc into thememory is set to a value four times greater (higher) than the speed fortaking out data from the memory, this invention is not limited to suchexamples, but higher speed may be employed within the realizable range.In addition, while capacity of the memory is set to 16 M bits, thisinvention is not limited to such an example also in this case, butmemory having arbitrary capacity may be used. It is to be noted that ifthese values are changed, it is a matter of course that lengths ofrespective time periods l₁ to l₉ shown in FIG. 16 would vary. Forexample, according as the capacity of a memory used becomes larger,lengths of respective time periods may be set to longer values.

Other circuit sections of the reproducing apparatus shown in FIG. 13will now be described.

The servo circuit section 77 delivers, to the optical pick-up 70, afocus servo control signal, a tracking servo control signal and a sledservo control signal in accordance with a servo circuit control signalas described above, which is delivered from the control section 76, tocarry out servo control of the optical pick-up 70. Moreover, the servocircuit section 77 delivers a rotation servo control signal to a spindlemotor 78 to carry out control of rotation of the spindle motor 78.

It is essentially required that the spindle motor 78 rotates at a speedhigher than that of the spindle motor of the ordinary CD player. Inorder that the speed for writing reproduction data into the memory whichtakes thereinto data from the recording medium is caused to be valuefour times higher than the speed for reading out reproduction data fromthe memory, rotation speed of the spindle motor 78 is set to a valuefour times higher than the rotation speed of the spindle motor of theordinary CD player. In addition, the spindle motor 78 may be caused torotate at a higher speed. By allowing the spindle motor 78 to rotate ata speed higher than that of the spindle motor of the ordinary CD player,reproduction of digital audio information from the CD-R disc 1 can becarried out by the above-described reproducing method.

The reproduction output section 79 comprises synthesis section,digital/analog converter, and audio amplifier, etc. More particularly,the synthesis section synthesize, on the basis of reproduction controlsignal from the control section 76, digital audio information from thefirst memory 72 and digital audio information from the second memory 73while taking synchronization therebetween. The digital/analog converterconverts the synthesized digital audio information into analog audiosignal. The audio amplifier amplifiers this audio signal to output itthrough an output terminal 80.

A modified example of the first embodiment of the reproducing apparatusto which this invention is applied will now be described.

In this reproducing apparatus, digital audio information recorded in thefirst recording area 3 of the first session 9 of the CD-R disc 1 isdigital audio information of 2 channels, e.g., forward channels, anddigital audio information recorded in the second recording area 6 of thesecond session 10 is digital audio information of 2 channels, e.g.,backward channels corresponding to the digital audio informationrecorded in the first recording area 3. This reproducing apparatus isadapted to reproduce digital audio information from the CD-R disc 1. Inaddition, digital audio information recorded in the second recordingarea 6 is digital audio information compressed, e.g., by the algorithmof ATRAC.

In the reproducing apparatus of this modified example, as shown in FIG.17, for example, the optical pick-up 70 provides access to the CD-R disc1 by the focus servo control signal, the tracking servo control signaland the sled servo control signal from the servo circuit section 77.Then, data of the CD-R disc 1 is read by the optical pick-up 70. Thedata thus obtained is delivered to a RF circuit 131 as a RF signal, andis delivered to a CD signal processing and time axis synchronization(sync.) circuit 132 after undergone waveform shaping and binarization.

The CD signal processing and time axis synchronization circuit 132 isoperative so that when management information recorded in the firstmanagement area 2 and the second management area 5 of data from the RFcircuit 131 are inputted thereto, it delivers those managementinformation to the control section 76. Moreover, the CD signalprocessing and time axis synchronization circuit 132 is operative sothat when program data (digital audio information) recorded in the firstrecording area 3 and the second recording area 6 are inputted thereto,it carries out CD signal processing, i.e., demodulates EFM data of theCD-DA format to deliver reproduction data thus obtained to the firstmemory 72.

On the other hand, the CD signal processing and time axissynchronization circuit 132 is operative so that when data of the CD-ROMformat is inputted thereto, it demodulates EFM data of the CD-ROM formatto deliver data thus obtained to a CD-ROM signal processing circuit 133.

Moreover, the CD signal processing and time axis synchronization circuit132 reads out reproduction data from the first memory 72 on the basis ofthe processing control signal and the memory control signal from thecontrol section 76 to output it through a forward channel outputterminal 137.

The first memory 72 has, e.g., capacity of 16 M bits, and serves totemporarily store reproduction data corresponding to the data recordedin the first recording area 3.

Then, the CD-ROM signal processing circuit 133 carries out errorcorrection of data of the CD-ROM format from the CD signal processingand time axis synchronization circuit 132 by using the error correctioncode for the CD-ROM format, or detects address information, etc. Then,the CD-ROM signal processing circuit 133 delivers reproduction data thusobtained to the second memory 73 and delivers address information to thecontrol section 76 through a memory control circuit 135. Namely, a ROM134 connected to the CD-ROM signal processing circuit 133 has, e.g.,capacity of 64 K bits, and data and/or program for error correction ordetection of address information are stored in this ROM 134. Then, theCD-ROM signal processing circuit 133 carries out error correction and/oraddress detection in accordance with such data and/or program.

The memory control circuit 135 delivers reproduction data delivered fromCD-ROM signal processing circuit 133, i.e., reproduction data obtainedfrom the second recording area 6 to the second memory 73. Moreover, thememory control circuit 135 reads out reproduction data from the secondmemory 73 in accordance with a memory control signal from the controlsection 76 to deliver it to an expansion decode processing circuit 136.The second memory 73 has, e.g., capacity of 16 M bits similarly to thefirst memory 72, and serves to temporarily store reproduction datacorresponding to the data recorded in the second recording area 6.

The expansion decode processing circuit 136 decodes reproduction datawhich has been read out from the second memory 73, i.e., data compressedinto data size of substantially 1/5 by using the algorithm of ATRAC tooutput reproduction data thus obtained through a backward channel outputterminal 138.

The control section 76 generates a servo circuit control signal forcontrolling the access operation with respect to the CD-R disc 1 of theoptical pick-up 70 on the basis of the management information and thereproduction data delivered from the CD signal processing and time axissynchronization circuit 132 to deliver this servo circuit control signalto the servo circuit section 77, and generates a processing controlsignal for controlling data processing at the CD signal processing andtime axis synchronization circuit 132 and the CD-ROM signal processingcircuit 133 to deliver it to the CD-ROM signal processing circuit 133.Moreover, the control section 76 generates a memory control signal fortaking out reproduction data from the first memory 72 to deliver it tothe CD-ROM signal processing circuit 133 through the CD signalprocessing and time axis synchronization circuit 132, and delivers amemory control signal for taking out reproduction data from the secondmemory 73 to the memory control circuit 135. Further, the controlsection 76 generates a decode control signal for controlling decodeoperation at the expansion decode processing circuit 136 on the basis ofthe CD-ROM format data from the CD-ROM signal processing circuit 133 todeliver it to the expansion decode processing circuit 136.

The servo circuit section 77 generates a focus servo control signal, atracking servo control signal and a sled servo control signal on thebasis of a servo circuit control signal delivered from the controlsection 76 to control the access operation with respect to the CD-R disc1 of the optical pick-up 70. In addition, the servo circuit section 77generates a rotation servo control signal for controlling rotationoperation of the spindle motor 78 to deliver it to the spindle motor 78.

As described above, the spindle motor 78 has a rotation speed higherthan that of the spindle motor of the ordinary CD player, and rotates,e.g., at a speed four times higher than that of the spindle motor of theordinary CD player.

Further, in this reproducing apparatus, in the case where CD-R disc 1such that digital audio information of the forward channels are recordedin the first recording area 3 and digital audio information of thebackward channels are recorded in the second recording area 6 isreproduced, data of the respective recording areas are read by theoptical pick-up 70. At this time, data from the first recording area 3is processed at the CD signal and time axis synchronization circuit 132,and is temporarily stored into the first memory 72. Moreover, data fromthe second recording area 6 is caused to undergo demodulation processingcorresponding to EFM at the CD signal processing and time axissynchronization circuit 132, and is then temporarily stored into thesecond memory 73 through the memory control circuit 135.

The control section 76 takes out reproduction data taken into the firstmemory 72 and reproduction data taken into the second memory 73 on thebasis of the memory control signal in such a manner that they aresynchronized with each other to output the reproduction data from thefirst memory 72 through the forward channel output terminal 137, and todecode the reproduction data from the second memory 73 at the expansiondecode processing circuit 136 thereafter to output it through thebackward channel output terminal 138.

Another modified example of the first embodiment of the reproducingapparatus will now be described.

In this reproducing apparatus, digital audio information recorded in thefirst recording area of the first session 9 of the CD-R disc 1 isdigital audio information obtained by sampling an audio signal at apredetermined frequency, e.g., 88.2 kHz thereafter to quantize it by apredetermined number of bits, e.g., 16 bits to band-divide the quantizeddigital audio information at a predetermined frequency, e.g., 22 kHz tosample, e.g., the digital audio information of the group of the lowerfrequency band side of 0 kHz˜22 kHz at a sampling frequency lower thanthe predetermined sampling frequency, e.g., 44.1 kHz; and digital audioinformation recorded in the second recording area 6 of the secondsession 10 is digital audio information obtained by compressing thedigital audio information of the group of the higher frequency band sideof 22 kHz˜44 kHz, e.g., by the algorithm of ATRAC. This reproducingapparatus is adapted to reproduce digital audio information from theCD-R disc 1.

The configuration of the reproducing apparatus of the second modifiedexample is shown in FIG. 18. It is to be noted that, in the followingdescription, the same reference numerals are respectively attached tothe same circuits as those of the reproducing apparatus shown in FIG. 17and their explanation will be omitted.

An output from the optical pick-up 70 is delivered to CD signalprocessing and time axis synchronization circuit 132 through RF circuit131 in a manner as described above. In this example, the accessoperation of the optical pick-up 70 is controlled by a servo controlsignal from the servo circuit section 77.

The CD signal processing and time axis synchronization circuit 132demodulates EFM data from the first recording area 3 to store it intothe first memory 72 as reproduction data of the CD-DA format standard.Moreover, the CD signal processing and time axis synchronization circuit132 demodulates EFM data from the second recording area 6 to deliver itto the CD-ROM signal processing section 133. Further, the CD signalprocessing and time axis synchronization circuit 132 takes outreproduction data from the first memory 72 on the basis of the memorycontrol signal from the control section 76 to deliver it to anoversampling circuit 140. In this example, the operation of the CDsignal processing and time axis synchronization circuit 132 iscontrolled by processing control signal from the control section 76.

The oversampling circuit 140 will now be described.

As described above, the digital audio information recorded in the firstrecording area 3 is the portion of 0 kHz˜22 kHz of data sampled at 88.2kHz. On the contrary, the oversampling circuit 140 is supplied with dataof the CD-DA format standard, i.e., data sampled at the samplingfrequency of 44.1 kHz. Accordingly, the oversampling circuit 140oversamples the data of the CD-DA format standard, e.g., at the samplingfrequency of 88.2 kHz to deliver oversampled data thus obtained to aband synthesis circuit 141.

On the other hand, as described above, the CD-ROM signal processingcircuit 133 carries out error correction of data recorded in the secondrecording area 6 and/or address processing thereof to deliverreproduction data thus obtained to the second memory 73 through thememory control circuit 135, and delivers address information to thecontrol section 76. In this example, the operation of the CD-ROM signalprocessing circuit 133 is controlled on the basis of the processingcontrol signal from the control section 76.

The memory control circuit 135 allows the second memory 73 to storetherein the reproduction data from the CD-ROM signal processing circuit133, and reads out the reproduction data from the second memory 73 onthe basis of memory control signal from the control section 76 todeliver it to the expansion decode processing circuit 136.

Since reproduction data which has been read out from the second memory73 is compressed by the algorithm of ATRAC, the expansion decodeprocessing circuit 136 decodes that reproduction data to deliver datathus obtained to the band synthesis circuit 141. In this example, thedata obtained by decode processing is the portion of 22 kHz˜44 kHz ofthe digital audio information sampled at 88.2 kHz. In addition, theexpansion decode processing circuit 136 is controlled on the basis ofdecode control signal from the control section 76.

The band synthesis circuit 141 synthesizes data of 0 kHz˜22 kHz sampledat the sampling frequency of 88.2 kHz delivered from the oversamplingcircuit 140 and data of 22 kHz˜44 kHz sampled at the sampling frequencyof 88.2 kHz delivered from the expansion decode processing circuit 136to output digital audio information within the range of 0 kHz˜44 kHzsampled at the sampling frequency of 88.2 kHz through a digital audioinformation output terminal 139. In this example, since taking-outoperation of reproduction data from the first memory 72 and taking-outoperation of reproduction data from the second memory 73 are controlledby the control section 76. Since digital audio information correspondingto each other are inputted to the band synthesis circuit 141 in thestate where their timings are in correspondence with each other, thereis no necessity of particularly taking synchronization therebetween.

Subsequently, a third modified example of the first embodiment of thereproducing apparatus will be described below.

In this reproducing apparatus, digital audio information recorded in thefirst recording area 3 of the first session 9 of the CD-R disc 1 isdigital audio information of high order, e.g., 16 bits of digital audioinformation obtained by sampling an audio signal at a predeterminedsampling frequency, e.g., 44.1 kHz thereafter to quantize the audiosignal thus sampled by a predetermined number of bits, e.g., 20 bits,and digital audio information recorded in the second recording area 6 ofthe second session 10 is digital audio information of low order 4 bitsof the quantized digital audio information. This reproducing apparatusis adapted to reproduce digital audio information from the CD-R disc 1.

The configuration of the reproducing apparatus of the third modifiedexample is shown in FIG. 19. It is to be noted that, in the followingdescription, the same reference numerals are respectively attached tothe same circuits as those of the reproducing apparatus of FIG. 17 andtheir explanation will be omitted.

An output from the optical pick-up 70 is delivered to the CD signalprocessing and time axis synchronization circuit 132 through RF circuit131. In this example, the access operation of the optical pick-up 70 iscontrolled by a servo control signal from the servo circuit section 77.

The CD signal processing and time axis synchronization circuit 132demodulates EFM data from the first recording area 3 to allow the firstmemory 72 to store it as reproduction data of the CD-DA format standard.Moreover, the CD signal processing and time axis synchronization circuit132 demodulates EFM data from the second recording area 6 to deliver itto the CD-ROM signal processing section 133. Further, the CD signalprocessing and time axis synchronization circuit 132 takes outreproduction data from the first memory 72 on the basis of the memorycontrol signal from the control section 76 to send it to a datasynthesis section 142. It is to be noted that data obtained in thisexample is data of high order 16 bits of digital audio information of 20bits sampled at the sampling frequency of 44.1 kHz, and only thisportion can be outputted as reproduction output. In addition, theoperation of the CD signal processing and time axis synchronizationcircuit 132 is controlled by the processing control signal from thecontrol section 76.

As described above, the CD-ROM signal processing circuit 133 carries outerror correction of data recorded in the second recording area 6 and/oraddress processing thereof to deliver reproduction data thus obtained tothe second memory through the memory control circuit 135, and deliversthe address information to the control section 76. In this case, theoperation of the CD-ROM signal processing circuit 133 is controlled onthe basis of processing control signal from the control section 76.

The memory control circuit 135 allows the second memory 73 to storetherein reproduction data from the CD-ROM signal processing circuit 133,and reads out the reproduction data from the second memory 73 on thebasis of the memory control signal from the control section 76 todeliver it to the data synthesis section 142. In this case, dataoutputted from the memory control circuit 135 is data of low order 4bits of digital audio information of 20 bits sampled at the samplingfrequency of 44.1 kHz.

The data synthesis section 142 synthesizes data of high order 16 bitsfrom the CD signal processing and time axis synchronization circuit 132and data of low order 4 bits from the memory control circuit 135 togenerate digital audio information of 20 bits in which the audio signalis sampled at the sampling frequency 44.1 kHz to output it through adigital audio information output terminal 143. In this example,taking-out operation of reproduction data from the first memory 72 andtaking-out operation of reproduction data from the second memory 73 arecontrolled by the control section 76. Accordingly, digital audioinformation corresponding to each other are inputted to the datasynthesis section 142 in the state where their timings are incorrespondence with each other. For this reason, there is no necessityof particularly taking synchronization therebetween.

Meanwhile, in any of the first to third modified examples, when data ofthe CD-ROM format recorded in the second recording area 6 is taken asdigital audio information including time code of data of thecorresponding first recording area 3, reproduction data are read outfrom the first memory 72 and the second memory 73 at the same time (inparallel) to synthesize them by making reference to the time code,thereby making it possible to reproduce high sound quality digital audioinformation.

A second embodiment of the reproducing apparatus to which this inventionis applied will now be described.

The reproducing apparatus of the second embodiment is directed to areproducing apparatus adapted for reproducing digital audio informationfrom CD-R disc 1 including, as shown in FIGS. 1A-1B, for example, firstrecording area 3 where digital audio information and address informationare recorded in multiplexed manner, first management area 2 whereinformation for carrying out management of the digital audio informationrecorded in the first recording area 3 is recorded, a second recordingarea 6 where digital audio information and address informationcorresponding to the first recording area 3 are recorded in multiplexedmanner, and second management area 5 where information for carrying outmanagement of the digital audio information recorded in the secondrecording area 6 is recorded, the reproducing apparatus comprising, asshown in FIGS. 20A-20C, for example, a first pick-up 151 and a firstsignal processing section 153 for reading digital audio information andaddress information from the first recording area 3, a second pick-up152 and a second signal processing section 154 for reading digital audioinformation and address information from the second recording area 6, aninternal memory 160 for storing digital audio information from thesecond signal processing section 154, a control section 155 forcontrolling the internal memory 160 and the second signal processingsection 154 on the basis of the address information from the firstrecording area 3 and the address information from the second recordingarea a 6, a mixing section 162 for mixing the digital audio informationreproduced by the first pick-up 151 and the digital audio informationreproduced by the second pick-up 152, and a D/A converting section 164for converting the digital audio information mixed by the mixing section162 into an analog audio signal to output it.

As described above, the CD-R disc 1 is an optical disc of multisessionsuch that the first session 9 is recorded by the CD-DA format, and thesecond session 10 is recorded by the CD-ROM format.

In operation, the first pick-up 151 reads the digital audio informationrecorded in the first session 9 to deliver a reproduction signal thusobtained to the first signal processing section 153. Moreover, the firstpick-up 151 provides access to the CD-R disc 1 on the basis of servocontrol signal or read stop signal which will be described later fromthe control section 155.

Further, the second pick-up 152 reads the digital audio informationrecorded in the second session 10 to deliver a reproduction signal thusobtained to the second signal processing section 154. In addition, thesecond pick-up 152 provides access to the CD-R disc 1 on the basis ofthe servo control signal or the read stop signal from the controlsection 155 similarly to the first pick-up 151.

The first signal processing section 153 binarizes the reproductionsignal from the first pick-up 151 to deliver data from the firstmanagement area 2 thus obtained to the control section 155, anddemodulates data from the first recording area 3 by the systemprescribed by the CD-DA format to deliver digital audio information of16 bits thus obtained to the mixing section 162 through a 16 bit datapath 156 to deliver address data of the digital audio information to theinternal memory 160 through an address data path 157.

The second signal processing section 154 binarizes the reproductionsignal from the second pick-up 152 to extract discrimination dataindicating kind (type) of the CD-R disc 1 from the second managementarea 5 to decode data from the second recording area 6 on the basis ofthe discrimination data. Moreover, the second signal processing section154 delivers data of the CD-ROM format thus obtained to the internalmemory 160 through a CD-ROM format data path 158 to deliver address dataof respective data to the internal memory 160 through an address datapath 159.

The internal memory 160 temporarily stores, as storage data, data of theCD-ROM format delivered from the second signal processing section 154,and delivers the storage data to the mixing section 162, while takingtiming so as to synchronize the timing when digital audio information of16 bits obtained at the first signal processing section 153 is outputtedto the mixing section 162, on the basis of address data delivered fromthe first signal processing section 153 and address data sent from thesecond signal processing section 154.

Moreover, the storage data is delivered also to a detecting section 161.The detecting section 161 estimates storage data quantity of theinternal memory 160 to deliver detection data thus obtained to thecontrol section 155.

The control section 155 delivers control signals to respective circuitcomponents of the reproducing apparatus of the second example(embodiment) on the basis of reproduction signal sent from the firstsignal processing section 153 and detection data sent from the detectingsection 161 to control the operations of respective circuit componentsin accordance with the flowchart showing the reproducing method by thereproducing apparatus of the second example (embodiment) shown in FIG.21.

Explanation will be given with reference to the flowchart shown in FIG.21, for example, in connection with the operation of the reproducingapparatus of the second embodiment, i.e., the reproducing method towhich this invention is applied.

The reproducing method to which this invention is applied is areproducing method for reproducing audio information from CD-R disc 1which is the recording medium including first recording area 3 wheredigital audio information and address information are recorded in amultiplexed manner, first management area 2 where information forcarrying out management of the digital audio information recorded in thefirst recording area 3 is recorded, second recording area 6 wheredigital audio information and address information corresponding to thefirst recording area 3 are recorded in a multiplexed manner, and secondmanagement area 5 where information for carrying out management of thedigital audio information recorded in the second recording area 6 isrecorded, the reproducing method including, as shown in FIG. 21, stepS107 of reading digital audio information and address information fromthe first recording area 3 by the first pick-up 151, step S108 ofreading digital audio information and address information from thesecond recording area 6 by the second pick-up 152, steps S112, S114 ofoutputting, on the basis of the digital audio information and theaddress information obtained at the step S107 and the digital audioinformation and the address information obtained at the step S108, thedigital audio information while taking synchronization therebetween,step S110 of discriminating whether or not information storage quantityof the internal memory 160 for temporarily storing digital audioinformation from the second pick-up 152 is a predetermined value ormore, step S113 such that in the case where it is discriminated at thestep S110 that storage quantity of information stored in the memorysection is the predetermined value or more, such a control is conductedto allow the second pick-up 152 to be in the standby state, step S115 ofdiscriminating whether or not information storage quantity of theinternal memory 160 is below the predetermined value, and step S116 suchthat in the case where it is below the predetermined value, such acontrol is conducted to re-start the second pick-up 152.

In this reproducing method, at step S100, the reproducing operation ofthe CD-R disc 1 is started. At step S101, the control section 155delivers a servo control signal to the first pick-up 151 so as allow itto provide access to the first management area 2 to allow the firstpick-up 151 to carry out reproduction of management information from thefirst management area 2. Then, the processing proceeds to step S102.

At step S102, whether or not information frame in which data PO shown inFIG. 5 is "B0" exists in management information delivered from the firstpick-up 151 (hereinafter referred to as first management information) isdiscriminated at the control section 155. Namely, whether or not thedisc being reproduced is multisession disc is discriminated. In the casewhere discrimination result is NO, i.e., the disc being reproduced issingle session disc, the processing proceeds to step S103. Thisreproducing apparatus carries out reproduction processing of theordinary disc.

On the other hand, in the case where discrimination result at the stepS102 is YES, i.e., it is discriminated that the disc being reproduced ismultisession disc, the processing proceeds to step S104. Whether or notinformation frame in which data PO is "E0" exists in the firstmanagement information is discriminated in turn. When thisdiscrimination result is NO, i.e., it is discriminated that the discbeing reproduced is the disc where only character data is recorded inthe second management area 5 of the second session 10 and no data isrecorded in the second recording area 6, the processing proceeds to stepS105. Thus, the reproducing apparatus carries out reproductionprocessing of the so-called disc with character.

On the other hand, in the case where the discrimination result at thestep S104 is YES, i.e., it is discriminated that the disc beingreproduced is the CD-R disc, the processing proceeds to step S106. Thus,the control section 155 delivers a servo control signal to the secondpick-up 152 so as to allow it to provide access to the second managementarea 5 on the basis of address information indicated by the firstmanagement information. Thus, the second pick-up 152 carries outreproduction of the second management area 5. Then, the processingproceeds to step S107.

At the step S107, the control section 155 delivers a servo controlsignal to the first pick-up 151 so as to allow it to provide access tothe first recording area 3 on the basis of address information indicatedby the first management information. Thus, the first pick-up 151reproduces program recorded in the first recording area 3.

Moreover, at step S108, the control section 155 delivers a servo controlsignal to the second pick-up 152 so as to allow it to provide access tothe second recording area 6 on the basis of address informationindicated by the second management information. Thus, the second pick-up152 reproduces program recorded in the second recording area 6.

At step S109, the control section 155 delivers memory control signal tothe internal memory 160. Thus, the internal memory 160 stores dataobtained by reproducing the second recording area 6.

Moreover, at step S110, the control section 155 discriminates on thebasis of detection data delivered from the detection section 161 whetheror not quantity of storage data of the internal memory 160 reaches apredetermined quantity, e.g., storage allowed quantity. In the casewhere this discrimination result is NO, i.e., sufficient empty areaexists in the internal memory 160, the processing proceeds to step S111.

At the step S111, whether or not reproduction of the second recordingarea 6 is completed is discriminated. In the case where thisdiscrimination result is NO, i.e., playing has not yet been completed,the processing proceeds to step S112. Thus, the control section 155delivers, to the internal memory 160, such a memory control signal tooutput storage data in a manner to allow address information obtained byreproducing the first recording area 3 and address information obtainedby reproducing the second recording area 6 to be synchronous with eachother while continuing the reproduction operation of the second pick-up152. Then, the processing returns to the step S109.

On the other hand, in the case where the discrimination result at thestep S111 is YES, i.e., playing has been completed, the processingproceeds to step S117. Thus, the control section 155 sends the read stopsignal to the first pick-up 151 and the second pick-up 152 to stop thereproduction operation. Then, this reproducing apparatus completes thereproducing operation.

Moreover, in the case where the discrimination result at the step S110is YES, i.e., it is discriminated that quantity of storage data of theinternal memory 160 reaches the storage allowed quantity so that it isimpossible to still more take thereinto data beyond that quantity, theprocessing proceeds to step S113. Thus, the control section 155 sendsthe read stop signal to the second pick-up 152. The second pick-up 152stops the reproduction operation and is caused to be on standby.

At step S114, the control section 155 delivers, to the internal memory160, similarly to the step S112, such a memory control signal to outputstorage data in the state where address information obtained byreproducing the first recording area 3 and address information obtainedby reproducing the second recording area 6 are synchronized with eachother. Then, the processing proceeds to step S115.

At the step S115, the control section 155 discriminates on the basis ofthe detection data from the detection section 161 whether or notquantity of the storage data is less than the predetermined value. Inthe case where this discrimination result is NO, i.e., it isdiscriminated that space area is not sufficiently ensured in theinternal memory 160, the processing returns to the step S113.

On the other hand, in the case where the discrimination result at thestep S115 is YES, i.e., it is discriminated that quantity of storagedata reaches the predetermined value so that sufficient space area isensured in the internal memory 160, the processing proceeds to stepS116. Thus, the control section 155 sends, to the second pick-up 152caused to be in standby state, such a control signal that it isre-started. Then, the processing returns to the step S110.

It is to be noted that the operation from the step S109 to the step S116is continued after playing has been completed.

In the case where the CD-R disc 1 is an optical disc of the multisessionsuch that digital audio information recorded in the first recording area3 is digital audio information of 2 channels and digital audioinformation recorded in the second recording area 6 is digital audioinformation of 2 channels corresponding to the digital audio informationrecorded in the first recording area 3, i.e., in the case where data ofthe forward channels are recorded in the first session 9 of the CD-Rdisc 1 by the CD-DA format and data of the backward channels arerecorded in the second session 10 by the CD-ROM format in the compressedstate, two information frames in which data PO of the managementinformation shown in FIG. 5 is "B0", "E0" exist in the first managementarea 2, and information frame in which data PO of the managementinformation shown in FIG. 5 is "D1" exists in the second management area5. These information frames serve as discrimination data fordiscriminating the optical disc of multichannels.

Thus, the control section 155 detects, at the step S102 and the stepS104 of the flowchart indicating the reproducing method of FIG. 21,information frame in which data PO is "B0" and information frame inwhich data PO is "E0" in the first management information from the firstpick-up 151, and detects, at the step S106, information frame in whichdata PO is "D1" in the second management information from the secondpick-up 152. Then, the control section 155 delivers, to the secondsignal processing section 154, a processing control signal fordesignating a signal processing method to carry out signal processingfor reproducing the second recording area 6 of the optical disccorresponding to the multichannel, e.g., to carry out expansionprocessing in reproducing compressed data.

Accordingly, the first signal processing section 153 outputs digitalaudio information of 16 bits of the forward channels, and the secondsignal processing section 154 outputs data of the backward channels.Thus, high sound quality digital audio information of 4 channels areoutputted from a digital audio information output terminal 165.

Further, in the case where the CD-R disc 1 is an optical disc adapted tocope with signals of which number of bits has been increased, such thatdigital audio information recorded in the first recording area 3 isdigital audio information of high order bits of digital audioinformation quantized by a predetermined number of bits after undergonesampling at a predetermined sampling frequency, and digital audioinformation recorded in the second recording area 6 is digital audioinformation of low order bits of the quantized digital audioinformation, i.e., in the case where, e.g., digital audio information ofhigh order 16 bits is recorded in the first session 9 of the CD-R disc 1by the CD-DA format, and digital audio information of low order 4 bitsis recorded in the second session 10 by the CD-ROM format in the statecompressed in accordance with, e.g., the above-described algorithm ofATRAC, i.e., digital audio information of which number of bits has beenincreased of 20 bits is recorded, two information frames in which dataPO of the management information shown in FIG. 5 is "B0", "E0" exist inthe first management area 2, and information frame in which data PO ofthe management information shown in FIG. 5 is "D2" exists in the secondmanagement area 5. These information frames serve as discrimination datafor the optical disc adapted to cope with signals of which number ofbits has been increased.

Thus, the control section 155 detects, at the step S102 and the stepS104 of the flowchart showing the reproducing method of FIG. 21,information frame in which data PO is "B0" and information frame inwhich data PO is "E0" in the first management information from the firstpick-up 151, and detects, at the step S106, information frame in whichdata PO is "D2" in the second management frame from the second pick-up152. Then, the control section 155 delivers, to the second signalprocessing section 154, a processing control signal for designating asignal processing method to carry out signal processing for reproducingthe second recording area 6 of the optical disc 2 adapted to cope withsignals of which number of bits has been increased, e.g., to carry outexpansion processing in reproducing compressed data.

Accordingly, the first signal processing section 153 outputs datarecorded by the CD-DA format, and the second signal processing section154 outputs data obtained as the result of the fact that information oflow order 4 bits has been caused to undergo expansion processing. Thus,high sound quality digital audio information of 20 bits is outputtedfrom the digital audio information output terminal 165.

Moreover, in the case where the CD-R disc 1 is an optical disc such thatdigital audio information recorded in the first recording area 3 isdigital audio information obtained by band-dividing, at a predeterminedfrequency, e.g., 22 kHz which is one fourth (1/4) of sampling frequency,digital audio information sampled at a predetermined sampling frequency,e.g., 88.2 kHz and quantized by a predetermined number of bits, e.g., 20bits so that grouping into the digital audio information of the higherfrequency band side and the digital audio information of the lowerfrequency band side is carried out to sample, e.g., the digital audioinformation of the lower frequency side at a sampling frequency lowerthan the sampling frequency of 88.2 kHz, e.g., 44.1 kHz i.e., to carryout down-sampling, and digital audio information recorded in the secondrecording area 6 is digital audio information adapted to cope with theso-called high-sampling data (data sampled at high sampling frequency),obtained by compressing the digital audio information of the higherfrequency side, e.g., by the above-described algorithm of ATRAC, i.e.,in the case where, e.g., data of the lower frequency band side (0 kHz˜22kHz) of signal sampled at the sampling frequency of 88.2 kHz is recordedin the first session 9 of the CD-R disc 1 after undergone down-sampling,and data of the higher frequency band side (22 kHz˜44 kHz) is recordedin the second session 10 by the CD-ROM format in the compressed state,two information frames in which data PO of the management informationshown in FIG. 5 is "B0", "E0" exist in the first management area 2, andinformation frame in which data PO of the management information shownin FIG. 5 is "D3" exists in the second management area 5. Thesediscrimination frames serve as discrimination data for the optical disccorresponding to multichannel.

Thus, the control section 155 detects, at the step S102 and the stepS104 of the flowchart showing the reproducing method of FIG. 21,information frame in which data PO is "B0" and information frame inwhich data PO is "E0" in the first management information from the firstpick-up 151, and detects, at the step S106, information frame in whichdata PO is "D3" in the second management information from the secondpick-up 152. Then, the control section 155 delivers, to the secondsignal processing section 154, a processing control signal whichdesignates a signal processing method to carry out signal processing forreproducing the second recording area 6 of the optical disc adapted tocope with increased number of bits, e.g., to carry out expansionprocessing in reproducing compressed data.

Accordingly, the first signal processing section 153 outputs datarecorded by the CD-DA format, and the second signal processing section154 expands compressed digital audio information to output it. Thus,high sound quality digital audio information of 20 bits sampled at thesampling frequency of 88.1 kHz is outputted from the digital audioinformation output terminal 165.

It is to be noted that while the example of the CD-R disc includingplural sessions on the same surface was taken as the recording medium ofthis invention, and the examples of the recording apparatus forrecording data on such a CD-R disc, and the reproducing method and thereproducing apparatus for reproducing such CD-R disc were taken, thisinvention is not limited to such implementation. For example, thisinvention can be applied to, e.g., a multimedia optical disc as arecording medium including multilayer structure, e.g., a multimediaoptical disc such that data of the CD-DA format is recorded at the firstlayer and data of the CD-ROM format is recorded at the second layer, anda recording apparatus, a reproducing method and a reproducing apparatusfor such multimedia optical disc.

Industrial Applicability

As described above, in accordance with the recording medium of thisinvention, data can be recorded by different formats with respect to thefirst session 9 and the second session 10, respectively. Further,digital audio information to be recorded by the CD-DA format is recordedinto the first session 9, and digital audio information attached to thedigital audio information recorded in the first session 9 is recordedinto the second session 10, thereby making it possible to prepare arecording medium adapted so that audio data can be recorded in the stateof high sound quality and compatibility with the conventional CD playeris maintained.

Moreover, the recording medium is caused to be a recording medium suchthat digital audio information of 4 channels are recorded by 2 channelsin respective sessions in such a manner that digital audio informationis recorded at least in the first session by the CD-DA format, therebymaking it possible to prepare a recording medium adapted so that audiodata can be recorded in the state of high sound quality and maintaincompatibility with the conventional CD player is maintained.

Further, the recording medium is caused to be a recording medium suchthat the portion up to 16 bits of digital audio information more than 16bits is recorded into the first session 9 by the CD-DA format, anddigital audio information of the remaining bits is recorded into thesecond session 10, e.g., by the CD-ROM format. Thus, a recording mediumadapted so that audio data can be recorded in the state of high soundquality and compatibility with the conventional CD player is maintainedcan be prepared.

Further, the recording medium is caused to be a recording medium suchthat digital audio information sampled by the sampling frequencyprescribed (specified) by the ordinary CD-DA format is band-divided at apredetermined frequency, e.g., a frequency which is one half (1/2) ofthe sampling frequency so that grouping into digital audio informationof the higher frequency band side and digital audio information of thelower frequency band side of the frequency is made to down-sample thedigital audio information of the lower frequency band side to record itinto the first session 9 by the CD-DA format, and to record the digitalaudio information of the higher frequency band side into the secondsession 10, e.g., by the CD-ROM format. Thus, the recording mediumadapted so that audio data can be recorded in the state of high soundquality and compatibility with the conventional CD player is maintainedcan be prepared.

Further, in accordance with the recording apparatus of this invention,data can be respectively recorded by different formats with respect tothe first session 9 and the second session 10. Further, digital audioinformation to be recorded by the CD-DA format is recorded into thefirst session 9, and digital audio information attached to the digitalaudio information recorded in the first session 9 is recorded into thesecond session. Thus, the recording medium adapted so that audio datacan be recorded in the state of high sound quality and maintaincompatibility with the conventional CD player is maintained can beprepared.

Further, in accordance with the reproducing method of this invention,reproduction of a recording medium such that digital audio informationis recorded in the first recording area 3 and digital audio informationcorresponding to the digital audio information recorded in the firstrecording area 3 is recorded in the second recording area 6 is carriedout by reading and reproducing respective digital audio informationcorresponding to each other recorded in the first and second recordingareas 3 and 6 to synchronously output them. Thus, reproduction ofdigital audio information can be carried out without damaging soundquality from the recording medium on which digital audio information isrecorded in the state of high sound quality.

Further, in the reproduction method, in the case where there is used arecording medium such that digital audio information of 2 channels arerecorded in the first recording area 3 and digital audio information of2 channels corresponding to the digital audio information recorded inthe first recording area 3 are recorded in the second recording area 6,the digital audio information recorded in the first recording area 3 andthe digital audio information recorded in the second recording area 6are respectively read and reproduced, and are outputted in a mannersynchronized with each other. Thus, reproduction of information of highsound quality digital audio information of multichannel can be carriedout.

Further, in the reproducing method, in the case where there is used arecording medium such that the portion up to 16 bits of digital audioinformation more than 16 bits is recorded in the first recording area 3,and digital audio information of the remaining bits is recorded in thesecond recording area 6, the digital audio information recorded in thefirst recording area 3 and the digital audio information recorded in thesecond recording area 6 are respectively read and reproduced to outputthem in a manner synchronized with each other. Thus, reproduction ofhigh sound quality digital audio information of which number of bits hasbeen increased can be carried out.

Further, in the reproducing method, in the case where there is used arecording medium such that information obtained by band-divide, at apredetermined frequency, e.g., frequency which is one half (1/2) ofsampling frequency, digital audio information sampled at the samplingfrequency prescribed (specified) by the ordinary CD-DA format todown-sample the digital audio information of the lower frequency bandside with respect to the frequency which is one half (1/2) of thesampling frequency is recorded in the first recording area 3, andinformation obtained by compressing the digital audio information of thehigher frequency band side is recorded in the second recording area 6,an approach is employed to reproduce the digital audio information fromthe first recording area 3, and to reproduce compressed information fromthe second recording area 6 after undergone expansion processing tooutput digital audio information corresponding to each other in a mannersynchronized with each other. Thus, reproduction of high sound qualitydigital audio information of the so-called high-sampling system (sampledat high sampling frequency) can be carried out.

Further, in accordance with the reproducing apparatus of this invention,reproduction of a recording medium such that digital audio informationis recorded in the first recording area 3 and digital audio informationcorresponding to the digital information recorded in the first recordingarea 3 is recorded in the second recording area 6 is carried out, byusing single reproducing means, by reading and reproducing the digitalaudio information recorded in the first and second recording area 3, 6to output respective digital audio information corresponding to eachother in a manner synchronized with each other. Thus, it becomespossible to carry out reproduction of digital audio information withoutdamaging sound quality from the recording medium on which digital audioinformation is recorded in the state of high sound quality.

Further, in the reproducing apparatus, in the case where there is used arecording medium such that digital audio information of 2 channels arerecorded in the first recording area 3 and digital audio information of2 channels corresponding to the digital audio information recorded inthe first recording area 3 is recorded in the second recording area 6,the digital audio information recorded in the first recording area 3 andthe digital audio information recorded in the second recording area 6are read and reproduced by reproducing means to allow the control meansto conduct a control so as to output digital audio informationcorresponding to each other in a manner synchronized with each other.Thus, reproduction of high sound quality digital audio information ofmultichannel can be carried out.

Further, in the reproducing apparatus, in the case where there is used arecording medium such that the portion up to 16 bits of digital audioinformation more than 16 bits is recorded in the first recording area 3,and digital audio information of the remaining bits is recorded in thesecond recording area 6, the digital audio information recorded in thefirst recording area 3 and digital audio information recorded in thesecond recording area 6 are read and reproduced by reproducing means toallow the control means to conduct a control to output digital audioinformation corresponding to each other in a manner synchronized witheach other. Thus, reproduction of high sound quality digital audioinformation of which number of bits has been increased can be carriedout.

Further, in the reproducing apparatus, in the case where there is used arecording medium such that information obtained by band-dividing, at apredetermined frequency, e.g., a frequency which is one half (1/2) ofsampling frequency, digital audio information sampled at the samplingfrequency prescribed (specified) by the ordinary CD-DA format todown-sample the digital audio information of the lower frequency bandside with respect to the frequency which is one half (1/2) of thesampling frequency is recorded in the first recording area 3, andinformation obtained by compressing the digital audio information of thehigher frequency band side is recorded in the second recording area 6,reproducing means is caused to read and reproduce the digital audioinformation recorded in the first recording area 3, and to readcompressed digital audio information from the second recording area 6 toexpand the digital audio information thus read to reproduce it, andcontrol means is caused to conduct a control so as to output digitalaudio information corresponding to each other in a manner synchronizedwith each other. Thus, reproduction of high sound quality digital audioinformation of the so called high-sampling (sampled at high samplingfrequency) can be carried out.

Further, in accordance with the reproducing apparatus of this invention,reproduction of a recording medium such that digital audio informationis recorded in the first recording area, and digital audio informationcorresponding to the digital audio information recorded in the firstrecording area 3 is recorded in the second recording area 6 is carriedout by using two reproducing means, by taking out the digital audioinformation recorded in the first and second recording areas 3, 6 tooutput respective digital audio information corresponding to each otherby mixing means in a manner synchronized with each other. Thus, itbecomes possible to carry out reproduction of digital audio informationwithout damaging the sound quality from the recording medium on whichdigital audio information is recorded in the state of high soundquality.

Further, in the reproducing apparatus, in the case where there is used arecording medium such that digital audio information of 2 channels arerecorded in the first recording area 3 and digital audio information of2 channels corresponding to the digital audio information recorded inthe first recording area 3 are recorded in the second recording area 6,first reproducing means is caused to read and reproduce the digitalaudio information recorded in the first recording area 3, secondreproducing means is caused to read and reproduce the digital audioinformation recorded in the second recording area 6, and mixing means iscaused to output digital audio information corresponding to each otherfrom the first and second reproducing means in a manner synchronizedwith each other. Thus, reproduction of high sound quality digital audioinformation of multichannel can be carried out.

Further, in the reproducing apparatus, in the case where there is used arecording medium such that the portion up to 16 bits of digital audioinformation more than 16 bits is recorded in the first recording area 3,and digital audio information of the remaining bits is recorded in thesecond recording area 6, digital audio information recorded in the firstrecording area 3 is read and reproduced by first reproducing means,digital audio information recorded in the second recording area 6 isread and reproduced by second reproducing means, and digital audioinformation corresponding to each other are outputted in a mannersynchronized with each other by mixing means. Thus, reproduction of highsound quality digital audio information of which number of bits has beenincreased can be carried out.

In addition, in the reproducing apparatus, in the case where there isused a recording medium such that information obtained by band-dividing,at a predetermined frequency, e.g., frequency which is one half (1/2) ofsampling frequency, digital audio information sampled at the samplingfrequency prescribed (specified) by the ordinary CD-DA format todown-sample the digital audio information of the lower frequency bandside with respect to the frequency which is one half (1/2) of thesampling frequency is recorded in the first recording area 3, andinformation obtained by compressing the digital audio information of thehigher frequency band side is recorded in the second recording area 6,the digital audio information recorded in the first recording area 3 isrecorded and reproduced by first reproducing means, the compresseddigital audio information is read from the second recording area bysecond reproducing means to expand the digital audio information thusread to reproduce it, and digital audio information corresponding toeach other from the first and second reproducing means are outputted ina manner synchronized with each other by mixing means. Thus,reproduction of high sound quality digital audio information of theso-called high-sampling system (sampled at high sampling frequency) canbe carried out.

What is claimed is:
 1. A recording medium on which a digital audiosignal sampled by a predetermined sampling frequency and quantized by apredetermined number (X+Y) of bits is recorded, the recording mediumcomprising:a first recording area where a digital audio signal sampledby the predetermined sampling frequency and quantized by X bits of the(X+Y) bits is recorded; a first management area where first managementdata is recorded in order to manage the digital audio signal recorded onthe first recording area; a second recording area where a digital audiosignal sampled by the predetermined sampling frequency and quantized byY bits of the (X+Y) bits is recorded, wherein said first and secondrecording areas are separate radial areas; and a second management areawhere second management data is recorded in order to manage the digitalaudio signal recorded on the second recording area.
 2. A recordingmedium as set forth in claim 1,wherein the digital audio signal recordedin the first recording area is digital audio signals of 2 channels, andwherein the digital audio signal recorded in the second recording areais digital audio signals of 2 channels corresponding to the digitalaudio signals of 2 channels recorded in the first recording area.
 3. Arecording medium as set forth in claim 1,wherein the digital audiosignal recorded in the second recording area is a compressed signal. 4.A recording medium as set forth in claim 1,wherein time codecorresponding to the first recording area is recorded in the secondrecording area.
 5. A recording medium on which a multi-channel digitalaudio signal is recorded, each channel of the digital audio signal beingsampled by a predetermined sampling frequency and quantized by apredetermined number of bits, the recording medium comprising:a firstrecording area where one channel of the digital audio signal sampled bythe predetermined sampling frequency and quantized by the predeterminednumber of bits is recorded; a first management area where firstmanagement data is recorded in order to manage the digital audio signalrecorded on the first recording area; a second recording area whereanother channel of the digital audio signal sampled by the predeterminedsampling frequency and quantized by the predetermined number of bits isrecorded; and a second management area where second management data isrecorded in order to manage the digital audio signal recorded on thesecond recording area, wherein the digital audio signal recorded in thefirst recording area is one of data portions of high order bits and loworder bits obtained by dividing the digital audio signal quantized bythe predetermined number of bits, and wherein the digital audio signalrecorded in the second recording area is the other of the data portionsof the digital audio signal quantized by the predetermined number ofbits.
 6. A recording medium on which a digital audio signal sampled by apredetermined sampling frequency and quantized by a predetermined numberof bits and divided into two frequency bands is recorded, the recordingmedium comprising:a first recording area where the digital audio signalsampled by the predetermined sampling frequency quantized by thepredetermined number of bits, and divided to one frequency band isrecorded; a first management area where first management data isrecorded in order to manage the digital audio signal recorded on thefirst recording area; a second recording area where the digital audiosignal sampled by the predetermined sampling frequency, quantized by thepredetermined number of bits, and divided to another frequency band isrecorded, wherein said first and second recording areas are separateradial areas; and a second management area where second management datais recorded in order to manage the digital audio signal recorded on thesecond recording area.
 7. A recording medium as set forth in claim6,wherein the digital audio signal recorded in the first recording areais a digital audio signal obtained by down-sampling a digital audiosignal of one band of the two frequency bands obtained by band-dividingthe digital audio signal sampled at a predetermined sampling frequency,and wherein the digital audio signal recorded in the second recordingarea is a digital audio signal of the other frequency band obtained byband-dividing the digital audio signal sampled at the predeterminedsampling frequency.
 8. A recording medium on which a digital audiosignal sampled by a predetermined sampling frequency and quantized by apredetermined number (X+Y) of bits is recorded, the recording mediumcomprising:a first recording area where a digital audio signal sampledby the predetermined sampling frequency and quantized by X bits of the(X+Y) bits is recorded; a first management area where first managementdata is recorded in order to manage the digital audio signal recorded onthe first recording area; a second recording area where a digital audiosignal sampled by the predetermined sampling frequency and quantized byY bits of the (X+Y) bits is recorded, wherein the first and secondrecording areas are separate radial areas; and a second management areawhere second management data is recorded in order to manage the digitalaudio signal recorded on the second recording area,wherein the digitalaudio signal sampled at the predetermined sampling frequency andquantized by X bits of the predetermined number (X+Y) of bits recordedin the first recording area is a digital audio signal of high order bitsof the quantized digital audio signal, and wherein the digital audiosignal sampled at the predetermined sampling frequency and quantized byY bits of the predetermined number (X+Y) of bits recorded in the secondrecording area is a digital audio signal of low order bits of thequantized digital audio signal.
 9. A recording medium on which a digitalaudio signal sampled by a predetermined sampling frequency and quantizedby a predetermined number (X+Y) of bits is recorded, the recordingmedium comprising:a first recording area where a digital audio signalsampled by the predetermined sampling frequency and quantized by X bitsof the (X+Y) bits is recorded; a first management area where firstmanagement data is recorded in order to manage the digital audio signalrecorded on the first recording area; a second recording area where adigital audio signal sampled by the predetermined sampling frequency andquantized by Y bits of the (X+Y) bits is recorded, wherein the first andsecond recording areas are separate radial areas; and a secondmanagement area where second management data is recorded in order tomanage the digital audio signal recorded on the second recordingarea,wherein the digital audio signal recorded in the first recordingarea is digital audio information obtained by band-dividing, at thepredetermined frequency, digital audio information sampled by thepredetermined sampling frequency and quantized by the predeterminednumber (X+Y) of bits so that grouping into digital audio information ofa higher frequency band side and a lower frequency band side is carriedout to sample the digital audio information of one group at a samplingfrequency lower than the predetermined sampling frequency, and whereinthe digital audio signal recorded in the second recording area isdigital audio information obtained by compressing the digital audioinformation of the other group.
 10. A recording medium on which adigital audio signal sampled by a predetermined sampling frequency andquantized by a predetermined number (X+Y) of bits is recorded, therecording medium comprising:a first recording area where a digital audiosignal sampled by the predetermined sampling frequency and quantized byX bits of the (X+Y) bits is recorded; a first management area wherefirst management data is recorded in order to manage the digital audiosignal recorded on the first recording area; a second recording areawhere a digital audio signal sampled by the predetermined samplingfrequency and quantized by Y bits of the (X+Y) bits is recorded; and asecond management area where second management data is recorded in orderto manage the digital audio signal recorded on the second recordingarea, wherein the X bits are 16 bits and the Y bits are 4 bits.
 11. Arecording medium on which a digital audio signal sampled by apredetermined sampling frequency and quantized by a predetermined number(X+Y) of bits is recorded, the recording medium comprising:a firstrecording area where a digital audio signal sampled by the predeterminedsampling frequency and quantized by X bits of the (X+Y) bits isrecorded; a first management area where first management data isrecorded in order to manage the digital audio signal recorded on thefirst recording area; a second recording area where a digital audiosignal sampled by the predetermined sampling frequency and quantized byY bits of the (X+Y) bits is recorded, wherein the first and secondrecording areas are separate radial areas; and a second management areawhere second management data is recorded in order to manage the digitalaudio signal recorded on the second recording area,wherein the X bits ofthe (X+Y) bits and the Y bits of the (X+Y) bits have different values.12. A recording medium on which a digital audio signal sampled by apredetermined sampling frequency and quantized by a predetermined number(X+Y) of bits is recorded, the recording medium comprising:a firstrecording area where a digital audio signal sampled by the predeterminedsampling frequency and quantized by X bits of the (X+Y) bits isrecorded; a first management area where first management data isrecorded in order to manage the digital audio signal recorded on thefirst recording area; a second recording area where a digital audiosignal sampled by the predetermined sampling frequency and quantized byY bits of the (X+Y) bits is recorded, wherein the first and secondrecording areas are separate radial areas; and a second management areawhere second management data is recorded in order to manage the digitalaudio signal recorded on the second recording area,wherein the X bitsare 16 bits and the Y bits are the predetermined number (X+Y) of bitsgreater than 16 bits.